Apparatus and method for positioning, implanting and using a stimulation lead

ABSTRACT

An introducing device for locating a tissue region and deploying an electrode is shown and described. The introducing device may include an outer sheath. An inner sheath may be disposed within the outer sheath. The inner sheath may be configured to engage an implantable electrode. In an example, the inner sheath may comprise a stimulation probe having an uninsulated portion at or near a distal end of the delivery sheath. The outer sheath may be coupled to a power source or stimulation signal generating circuitry at a proximal end. A clinician may control application of the stimulation signal to a tissue region via the outer sheath.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is continuation of and claims priority U.S. Utilityapplication Ser. No. 15/388,128 filed on Dec. 22, 2016 which is acontinuation of and claims priority to International Patent ApplicationSerial Number PCT/US16/57267 filed on Oct. 17, 2016 which, in turn,claimed priority to U.S. Patent Application Ser. No. 62/242,205 filed onOct. 15, 2015. The disclosure of these applications, along with anyother United States Patents and United States Patent Publicationsidentified in this specification, are hereby incorporated by reference.

FIELD OF INVENTION

The present disclosure generally relates to locating a target tissue anddeployment of a lead, and, more particularly, the disclosure relates toa system, apparatus, and methods for locating a target tissue region anddeploying a lead via a single handheld device.

BACKGROUND

Electrical stimulation systems have been used for the relief of chronicand acute pain as well as many other medical uses. There exist bothexternal and implantable devices for providing electrical stimulation toactivate nerves and/or muscles to provide therapeutic treatments. These“neurostimulators” are able to provide treatment and/or therapy toindividual portions of the body. The operation of these devicestypically includes the use of one or more electrodes placed either onthe external surface of the skin or a surgically implanted lead with oneor more electrodes. In many cases, surface electrode(s), cuff-styleelectrode(s), paddle-style electrode(s), or epidural-style orcylindrical-style electrodes and/or leads may be used to deliverelectrical stimulation to the select portion of the patient's body.

In some systems, an electrode(s) may be inserted into a bodypercutaneously. In these systems an electrode or a plurality ofelectrodes may be operatively positioned on a lead that ispercutaneously inserted into a patient. There exists a need for severaldevice improvements relating to the positioning and deploymentcapabilities of electrode leads used in various medical capacities,including electrical stimulation systems.

As described extensively in the literature, the existing systems anddevices for peripheral nerve stimulation may not meet the needs of theclinicians and patients. Existing systems can be inefficient; timeconsuming; and too invasive. They may also require prohibitivelyextensive training and skill to use; exhibit (or contribute to) poordevice performance/failure and suboptimal efficacy/effectiveness/safety;and prohibit use in patients and clinical settings that could benefitfrom electrical stimulation. In view of these deficiencies, there is alarge and unmet need for a device(s), system(s), and method(s) thatenables safe, effective, reliable, easy to use, and minimally-invasivedelivery of electrical stimulation lead(s) for the treatment of pain andother conditions.

Some conventional systems for electrode deployment or implantationcomprise two entirely separate procedures and device—first a test needleand then a second introducer/electrical lead. These systems, with twoseparate steps, may be inefficient, time consuming, and not ideal forpatients as this may require two separate needle insertions. Further,clinicians have also reported a need to view which direction a leadanchor of an electrode is facing once an introducer has been insertedinto a tissue of a patient. This viewing capability may aid in theeffective deployment of the lead and improve the efficiency of theprocedure. These systems rely upon carrying the lead within a singleneedle and deploying that needle by expelling the lead out of the openend of the needle. Owing to the relatively fragile nature of the leaditself, the ability to adjust the positioning of the lead—even smallamounts—is quite limited.

Another system is described in United States Patent Publication No.2007/0255368. Here, a coiled lead is placed in its desired location viaa small diameter needle. The lead is carried in the needle, and it has atines or sutures made of non-conductive material that expand after thelead is deployed out of the needle. The tines/sutures secure the lead inits desired location, but repositioning of the lead during the insertionprocess is difficult, if not impossible, owing to the lead's positioningin the needle and the non-conductive nature of its tines/sutures.Further, movement or removal of the lead after it is deployed will causetissue damage and disruption.

In view of the foregoing, a need exists for an improved system forelectrode deployment or implantation that allows for test stimulationand repositioning of the lead during positioning.

SUMMARY OF INVENTION

A wide variety of inter-related aspects of the invention are described.The features of any one specific embodiment disclosed or depicted hereinmay be applied to other embodiments, and additional features and aspectsof the system may be understood by those having skill in this field.

One aspect of the invention, an introducer system, has any combinationof the following features:

-   -   a electrical stimulus generator unit;    -   a needle assembly having an axial length, the needle assembly        including an outer sheath with a distal opening and an inner        deployment mechanism;    -   a stimulation electrode made from an electrically conductive        material, the electrode including a distal end having a bent        anchor portion and a terminal end and a proximal end in        communication with the stimulus generator unit;    -   wherein the bent anchor portion protrudes partially from the        distal opening and the terminal end is held within the needle        assembly between the inner deployment mechanism and an inner        facing of the outer sheath;    -   wherein inner deployment mechanism is positionable along the        axial length relative to the outer sheath so as to: (i) permit        free movement between a proximal, protected position in which        the electrode is substantially contained within the needle        assembly and a test position in which the bent anchor portion        protrudes sufficiently to deliver test stimulation from the        stimulus generator unit while the terminal end remains within        the needle assembly; and (ii) deploy the electrode at a final,        distal position so that the terminal end is released out of the        needle assembly;    -   wherein the inner deployment mechanism comprises an inner sheath        having a terminal opening with a first edge engaging the        partially protruding bent anchor portion;    -   wherein the inner sheath includes an aperture positioned        proximally from the terminal opening and wherein the aperture        has a second edge engaging the partially protruding bent anchor        portion;    -   wherein at least one of the first edge and the second edge is        fully rounded;    -   wherein the first edge is fully rounded;    -   wherein a groove extends between the terminal opening and the        aperture and wherein at least a portion of the partially        protruding bent anchor fits within the groove to minimize an        outer diameter in a distal portion of the needle assembly;    -   wherein the outer diameter in the distal portion of the needle        assembly at the distal end is substantially similar to an outer        diameter at a second point along the axial length of the needle        assembly;    -   wherein the terminal opening includes a bevel;    -   wherein a portion of the distal end of the outer sheath is        thinned to accommodate the partially protruding bent anchor        portion;    -   wherein the thinned portion comprises a groove;    -   wherein the inner deployment mechanism includes a stylet;    -   wherein the outer sheath includes a slot running along the axial        length of the outer sheath defined at its proximal end by the        distal opening;    -   wherein the partially protruding bent anchor portion moves        through the slot when the inner deployment mechanism is        repositioned from the proximal, protected position and the test        position;    -   a quick disconnection mechanism for maintaining contact between        the electrode and the stimulus generator unit;    -   wherein the quick disconnection mechanism includes at least one        aperture or slot and wherein a proximal end of the electrode is        received in the aperture or slot;    -   wherein the quick disconnection mechanism includes at least one        magnet;    -   wherein the quick disconnection mechanism includes an insulation        displacement connector;    -   wherein the quick disconnection mechanism includes at least one        biasing member;    -   a positioning block selectively coupled to the needle assembly        at an adjustable angle and rotation, the positioning block        selectively attachable to a subject to facilitate insertion,        repositioning, and test stimulation of the introducer system;    -   wherein the positioning block includes at least one adhesive        facing;    -   wherein the positioning block includes a locking mechanism        selectively inhibiting changes to at least one of the adjustable        angle and the rotation;    -   a user control connected to the stimulus generator unit;    -   wherein the user control includes a graphical user interface;    -   wherein the user control is wirelessly connected to the stimulus        generator unit;    -   wherein the needle assembly includes a spacer;    -   wherein the spacer is removable;    -   wherein the spacer moves in the axial length so as to retract at        least the outer sheath;    -   wherein the electrode comprises a coiled or helical structure;    -   wherein the coiled or helical structure promotes tissue        ingrowth;    -   wherein the inner deployment mechanism comprises a stylet at        least partially positioned on an inner-most portion of the        coiled or helical structure;    -   wherein the electrode comprises a biosorbable material;    -   wherein the bent anchor portion comprises the biosorbable        material;    -   wherein the proximal end of the stimulation electrode is        integrally coupled to a distal portion of a lead and wherein a        proximal portion of the lead is in communication with the        stimulus generating unit;    -   wherein the lead further comprises electrically insulating        material;    -   at least one test electrode positioned on the outer sheath;    -   a plurality of test electrodes positioned on the outer sheath;    -   wherein the at least one test electrode is in communication with        the stimulus generator unit;    -   wherein the plurality of test electrodes are positioned along        the axial length of the outer sheath at spaced-apart intervals;        and    -   wherein stimulation can be delivered through each of the test        electrodes individually, in concert, and/or in any combination.

Another aspect contemplates a method for delivering stimulation to aperipheral nerve system comprising any combination of the following:

-   -   attaching a stimulation electrode having a conductive distal        anchor to an inner deployment mechanism, including bending a        portion of the electrode including the distal anchor around a        distal end of the inner deployment mechanism;    -   positioning the electrode and inner deployment mechanism within        an outer sheath to create a two-part needle assembly;    -   connecting a proximal end of the needle assembly to a stimulus        generator unit;    -   inserting a distal end of the needle assembly into a peripheral        region of a human subject;    -   exposing the distal anchor to tissue in the human subject and        delivering test stimulation through the electrode to provide        therapy;    -   deploying the distal anchor and removing the needle assembly;    -   repositioning the needle assembly before deploying the distal        anchor to maximize therapeutic effects;    -   wherein the connecting the proximal end of the needle assembly        to stimulus generator unit includes creating at least one        breakaway connection in between the electrode and the stimulus        generator unit;    -   providing the human subject with a controller unit to optimize        at least one of: the delivering the test stimulation and        subsequent delivery of therapy after deploying the distal        anchor;    -   wherein the electrode is a coiled or helical structure having an        inner diameter and the inner deployment mechanism is provided in        an inner-most portion of the coiled or helical electrode;    -   wherein the electrode is provided within an inner lumen of the        inner deployment mechanism;    -   wherein the lumen includes an aperture proximate to but not in        communication with an opening at the distal end of the lumen and        wherein the electrode is threaded through the aperture so that        the distal end is positioned between the inner deployment        mechanism and an inner facing surface of the outer sheath; and    -   wherein the distal anchor is exposed by advancing the inner        lumen relative to the outer sheath and into the tissue but        without releasing the distal anchor from the needle assembly.

A further aspect considers an introducer system having any combinationof the following features:

-   -   a electrical stimulus generator unit;    -   a needle assembly having an axial length and an outer        circumference, the needle assembly including an outer sheath        with a distal opening, an inner deployment mechanism carried        within the outer sheath, and at least one test electrode        positioned along the outer circumference;    -   a stimulation electrode having a distal anchor and a proximal        end in communication with the stimulus generator unit, the        electrode carried within the needle assembly;    -   wherein the at least one test electrode delivers test        stimulation from the stimulus generator unit without deploying        the distal anchor;    -   wherein a portion of the electrode on or immediately proximate        to the distal anchor protrudes out of the inner deployment        mechanism and serves as the test electrode;    -   a slot positioned along the axial length of the needle assembly        so that the test electrode protrude through the slot;    -   wherein the inner deployment mechanism includes a plunger moving        along the axial length in concert with the test electrode;    -   a locking mechanism to prevent additional movement of the test        electrode prior to final deployment of the distal anchor and the        removal of the needle assembly; and    -   wherein a plurality of test electrodes are positioned on the        outer circumference.

A still further aspect considers an introducer system having anycombination of the following features:

-   -   a electrical stimulus generator unit;    -   a needle assembly having a length-wise axis, the needle assembly        including an outer sheath with a distal opening and an inner        sheath with a deployment mechanism;    -   a helical, open-coiled stimulation electrode made from an        electrically conductive material, the electrode including a        terminal end having a conductive anchor portion and a proximal        end communicating with the stimulus generator unit;    -   wherein the terminal end and at least a portion of the        conductive anchor portion are held within the needle assembly        between the inner sheath and an inner surface of the outer        sheath;    -   wherein the deployment mechanism and the outer sheath are        selectively movable in concert and in opposing directions along        the length-wise axis between a proximal protected position in        which the electrode is completely contained within the outer        sheath and a mid-point, test position in which the conductive        anchor portion protrudes through the distal opening to deliver        test stimulation from the stimulus generator unit while the        terminal end remains within the needle assembly;    -   wherein the conductive anchor portion and terminal end are        released out of the needle assembly when the deployment        mechanism and outer sheath are moved in opposing directions to a        releasing, distal position and subsequently retracted in        concert;    -   wherein all of the bent anchor is held within the needle        assembly; and    -   wherein at least one of the mid-point, test position and the        releasing, distal position include rotation of the inner sheath        relative to the outer sheath about the length-wise axis so as to        cause the conductive anchor portion to protrude through an        aperture in the outer sheath positioned proximate to the distal        opening.

Yet another aspect considers an introducer system having any combinationof the following features:

-   -   a electrical stimulus generator unit;    -   a needle assembly having a length-wise axis, the needle assembly        including an outer sheath with a distal opening and an inner        stylet moving freely within the outer sheath;    -   a helical, open-coiled stimulation electrode made from an        electrically conductive material, the electrode detachably        connected to the inner stylet and including a terminal end        having a conductive anchor portion and a proximal end        communicating with the stimulus generator unit;    -   wherein the terminal end and at least a portion of the        conductive anchor portion are held within the outer sheath;    -   wherein the inner stylet and the outer sheath are selectively        movable in concert and in opposing directions along the        length-wise axis between a proximal protected position in which        the electrode is completely contained within the outer sheath        and a mid-point, test position in which the conductive anchor        portion protrudes through the distal opening to deliver test        stimulation from the stimulus generator unit while the terminal        end remains within the needle assembly;    -   wherein the conductive anchor portion and terminal end are        released out of the needle assembly when the inner stylet and        outer sheath are moved in opposing directions to a releasing,        distal position and subsequently retracted in concert;    -   wherein the stylet is positioned within an inner-most portion of        the helical, open-coiled electrode;    -   wherein all of the bent anchor is held within the needle        assembly; and    -   wherein at least one of the mid-point, test position and the        releasing, distal position include rotation of the inner sheath        relative to the outer sheath about the length-wise axis so as to        cause the conductive anchor portion to protrude through an        aperture in the outer sheath positioned proximate to the distal        opening.

A further aspect considers an introducer system having any combinationof the following features:

-   -   an electrical stimulus generator unit;    -   a needle assembly including an outer sheath with a distal        opening, an inner deployment mechanism carried within the outer        sheath, and at least one test electrode positioned along an        outer circumference of the needle assembly and communicating        with the stimulus generator unit;    -   a stimulation lead comprising a monopolar electrode forming a        portion of a selectively deployable anchor at a distal end of        the lead, the stimulation lead communicating with the stimulus        generator unit;    -   wherein the monopolar electrode comprises a plurality of        mechanically integrated strands of an electrically conductive        material wound together in the form of a helix having a central        void space;    -   wherein the needle assembly is inserted into a patient and        optionally repositioned based upon the at least one test        electrode delivering test stimulation from the stimulus        generator unit until an optimal location is identified;    -   wherein, when the inner deployment mechanism is moved relative        to the outer sheath, the distal end releases out of the needle        assembly and the deployable anchor is fixed at the optimal        location to deliver regular stimulation from the stimulus        generator unit to the optimal location;    -   wherein a plurality of test electrodes are positioned along the        outer circumference;    -   wherein the test stimulation is delivered by the plurality of        electrodes to identify the optimal location without        repositioning the needle assembly and wherein the inner        deployment mechanism is moved to position the deployable anchor        at the optimal location when the needle assembly is retracted        out of the patient;    -   wherein the deployment mechanism comprises an inner sheath;    -   wherein the deployable anchor protrudes out of a distal opening        in the inner sheath and wherein the distal end is positioned        between the inner and outer sheaths prior to the release of the        distal end; and    -   wherein at least a portion of the deployment mechanism is        carried in the central void.

One aspect considers an introducer system having any combination of thefollowing features:

-   -   an electrical stimulus generator unit;    -   a needle assembly having an axial length and an outer        circumference, the needle assembly including an outer sheath        with a distal opening, an inner sheath or an inner stylet        deployment mechanism carried within the outer sheath, and at        least one test electrode positioned along the outer        circumference and capable of electrically communicating with the        stimulus generator unit;    -   a helical, open-coil stimulation lead made from an electrically        conductive material at least partially covered by an        electrically insulating material and having an electrode        including a coiled section of electrically conductive material        formed into a mechanical anchor at a terminal end coupled to the        distal end of the lead, and the lead also having a proximal end        capable of electrically communicating with the stimulus        generator unit; and    -   wherein the at least one test electrode delivers test        stimulation from the stimulus generator unit without deploying        the distal anchor and allowing the entire needle assembly to be        fully re-positionable until the terminal end is released from        the needle assembly.

A final aspect considers an introducer system having any combination ofthe following features:

-   -   an electrical stimulus generator unit;    -   a needle assembly having an axial length and an outer        circumference, the needle assembly including an outer sheath        with a distal opening, an inner deployment mechanism carried        within the outer sheath, and at least one test electrode        positioned along the outer circumference and capable of        electrically communicating with the stimulus generator unit;    -   a stimulation lead made from an electrically conductive material        and an electrically insulating material and having an electrode        including a bent anchor portion at a terminal end coupled to a        distal end of the lead, and the lead including a proximal end        capable of electrically communicating with the stimulus        generator unit; and    -   wherein the at least one test electrode delivers test        stimulation from the stimulus generator unit without deploying        the distal anchor.

While individual aspects of the invention are recited above, it ispossible to couple specific features and limitations associated with oneaspect to that of another aspect. Further, the functions and actionsassociated with the method aspect may further inform the structuralfeatures of apparatus aspects noted herein. Any of these foregoingfeatures may form the basis for subsequent claims to still furtheraspects of the invention, even though all of those aspects may not beindividually recited herein.

BRIEF DESCRIPTION OF THE DRAWINGS

Operation of the invention may be better understood by reference to thedetailed description taken in connection with the followingillustrations. These appended drawings form part of this specification,and written information in the drawings should be treated as part ofthis disclosure. In the drawings:

FIG. 1 is a partial, cross-sectional view of an introducing system withan un-deployed lead, in accordance with described aspects;

FIGS. 2A through 2D are partial, cross-sectional views of an introducingsystem as the lead is being deployed, in accordance with describedaspects, while FIG. 2E includes partial cross-sectional views of anintroducing system as the lead is being deployed along orthogonal axes(i.e., side view, front view, and—with respect to the first set ofimages—top view);

FIGS. 3A and 3B are cross sectional side views of an introducing needlehaving multiple test electrodes positioned around the exterior surfaceof the outer sheath;

FIG. 3C is a combination of side and axial cross sectional views of anintroducing needle having a series of slits to provide for teststimulation by the electrode itself;

system with an inner sheath having a first bevel level and an outersheath having a second bevel level, in accordance with describedaspects;

FIG. 4 is a cross-sectional view of an introducing system with an outersheath having a grooved formed in an inner surface, in accordance withdescribed aspects;

FIG. 5 is a perspective view of an introducing system with an innersheath and an outer sheath in a window configuration, in accordance withdescribed aspects;

FIGS. 6, 7A, and 8 are views of an introducing system showingalternative delivery mechanisms, in accordance with described aspects;

FIG. 9A is a perspective view of various bevels of sheaths, inaccordance with described aspects;

FIG. 9B are perspective and cross sectional views of modifications tothe outer sheath that minimize the overall profile of the needle/distalelectrode combination, in accordance with described aspects;

FIG. 9C are perspective views of embodiments in which the distal sectionof the electrode is secured to the sheath in accordance with describedapects;

FIG. 9D are top and cross sectional side views of embodiments in whichthe distal section of the electrode is secured to the sheath inaccordance with described aspects;

FIG. 10 is a perspective view of an introducing system within aninclined member of an inner sheath, in accordance with describedaspects;

FIG. 11 is a perspective view of a proximal end of an outer sheath of anintroducing system, in accordance with described aspects;

FIGS. 12A and 12B are perspective views of certain embodiments of theconnection between the lead and the lead connector in accordance withdescribed aspects;

FIG. 13 is a perspective view of certain embodiments of the introducersystem's ergonomic features in accordance with described aspects;

FIGS. 14A through 14E are views of certain embodiments for the deliverymechanism in accordance with described aspects;

FIGS. 15A and 15B illustrate spacer mechanisms in accordance withdescribed aspects;

FIGS. 16A through 16C illustrate exemplary stimulation patterns usefulin accordance with described aspects;

FIG. 17 depicts a type of graphical user interface that may be includedin accordance with described aspects;

FIGS. 18A and 18B illustrate ways in which stimulation intensity may beadjusted in accordance with described aspects;

FIG. 19 is a cross sectional side view of two separate prior artneedles;

FIG. 20A is a cross sectional side view, FIG. 20B a partial cut-awayperspective view, and FIG. 20C a full perspective view of needle havingfully rounded facings to accommodate an electrode in accordance withdescribed aspects;

FIGS. 21A and 21B depict exemplary embodiments of the insulationdisplacement connector in accordance with described aspects;

FIGS. 22A through 22D illustrate various arrangements for the quickdisconnect features contemplated in accordance with described aspects;

FIG. 23 is a perspective view of the bandage system in accordance withdescribed aspects;

FIGS. 24A through 24F illustrate how the bandage system may be appliedor replaced in accordance with described aspects; and

FIGS. 25A through 25C are schematic representations of quick disconnectfeatures contemplated in accordance with described aspects.

DETAILED DESCRIPTION

Reference will now be made in detail to exemplary embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. It is to be understood that other embodiments may be utilizedand structural and functional changes may be made without departing fromthe respective scope of the invention. Moreover, features of the variousembodiments may be combined or altered without departing from the scopeof the invention. As such, the following description is presented by wayof illustration only and should not limit in any way the variousalternatives and modifications that may be made to the illustratedembodiments and still be within the spirit and scope of the invention.

Any elements described herein as singular can be pluralized (i.e.,anything described as “one” can be more than one). Any species elementof a genus element can have the characteristics or elements of any otherspecies element of that genus. The described configurations, elements orcomplete assemblies and methods and their elements for carrying out theinvention, and variations of aspects of the invention can be combinedand modified with each other in any combination. As used herein, thewords “example” and “exemplary” mean an instance, or illustration. Thewords “example” or “exemplary” do not indicate a key or preferred aspector embodiment. The word “or” is intended to be inclusive rather anexclusive, unless context suggests otherwise. As an example, the phrase“A employs B or C,” includes any inclusive permutation (e.g., A employsB; A employs C; or A employs both B and C). As another matter, thearticles “a” and “an” are generally intended to mean “one or more”unless context suggest otherwise.

Described herein are systems, apparatuses, and methods that mayconveniently provide and/or facilitate a single deployment device toincorporate implantation of a lead. The lead (also referred to as amicro-lead, fine-wire lead or simply electrode) may possess a generallysmall diameter in comparison to previous systems, with optimal sizes ofless than 1.0 mm and, more preferably, less than 0.6 mm. Further, theelectrode may have a generally coiled or helical structure, rather thana smooth cylinder. However, the present teachings are not limited tothis structure of lead. Any appropriate configuration may be utilizedwithout departing from the present teachings. In an aspect, embodimentsdescribed herein may conveniently provide a single device that maylocate a desired tissue region, test stimulation of the tissue region,position (or reposition) a testing signal, and/or deploy an electrode orlead. The example embodiments may enable repositioning of the device andlead within human or animal tissue without deploying the electrode orlead until its deployment is desired by the user (e.g., the clinician).Embodiments may provide an easy to use and safe systems, apparatuses,and/or methods.

For the sake of clarity, the term “proximal” in the context of thisapplication typically refers to the end of the electrode that is notinserted into the body and “distal” typically refers to the electrodeend that is inserted into the body near the nerves. Depending upon themanufacture of the electrode structure, this proximal end may be wrappedin an insulating or protective coating or wrap. To the extent electricalconnections must be made with the proximal end, the components at issuewill allow for the removal of such coating(s)/wrap(s). The coating/wrapmay include markings to serve as indicia of mobility that help to gaugewhether the electrode has been repositioned or dislodged during systemuse, and particularly when outside of the oversight of a clinician.

As used herein, the terms inner sheath, introducer, introducing needle,inner needle, inner probe, introducing member, and/or the like areutilized interchangeably unless context suggests otherwise or warrants aparticular distinction among such terms. The terms outer sheath,delivery needle, outer needle, outer probe, outer member, and/or thelike are utilized interchangeably unless context suggests otherwise orwarrants a particular distinction among such terms.

The introducing device may enable a lead to be percutaneously placed asafe distance from a surgical site, which may increase safety, minimizerisk to the anatomy that is the focus of the surgery, minimize the riskof infection, and minimize the potential impact of any infection shouldit occur. As a non-limiting example, the device may enable placement ofthe lead to deliver stimulation to a nerve innervating a region, wherethe region may be painful or be anticipated to be painful due to asurgery (e.g., the device may enable placement of a lead to deliverstimulation to a femoral nerve, sciatic nerve, or lumbar plexusinnervating a region, such as a knee which may be undergoing kneereplacement surgery), and the device desirably enables the lead to beplaced a safe distance (e.g., in the upper thigh, upper leg, or lowerback) away from the surgical site (e.g., the knee) and/or outside of thesurgical field.

The introducing device may enable a target nerve to be identified priorto lead placement and prior to lead deployment as part of a non-surgicalprocedure.

There is a clinical need for a device that delivers therapeuticelectrical stimulation (e.g. peripheral nerve stimulation (PNS)) to anerve (e.g. peripheral nerve) innervating the region of pain to providepain relief. The device may deliver stimulation to the nervetransmitting the pain signal or it may deliver stimulation to a nerve,which is not transmitting the pain signal, but when stimulation isdelivered, a condition or symptom, such as pain, may be relieved orimproved and/or function may be improved or restored. The device maydeliver pain-relieving or function-restoring peripheral nervestimulation in a variety of settings including chronic, acute,post-surgical, post-traumatic, and intermittent pain and/or loss offunction, and other conditions (e.g., other types of pain and/orfunctional loss), as well as across a range of anatomical regions,including but not limited to limbs (e.g., arms, legs, etc.), extremities(e.g., hands, feet, fingers, toes, etc.), joints (e.g., hips, knees,shoulders, elbows, ankles, wrists, etc.), back, neck, head, face, andother regions.

The device may enable the delivery of electrical stimulation to providepain relief or functional improvement immediately following surgery. Thedevice may also improve function, strength, and range of motionfollowing surgery, as well as accelerate post-op recovery. The devicemay enable delivery of stimulation before, during, and after surgery, aswell as in scenarios not involving surgery, such as acute or chronicconditions within or outside of the context of surgery.

Additional embodiments of a percutaneous stimulation system according tothe present teachings are described below. In the descriptions, all ofthe details and components may not be fully described or shown. Rather,the main features or components are described and, in some instances,differences with the above-described embodiment may be pointed out.Moreover, it should be appreciated that these additional embodiments mayinclude elements or components utilized in the above-describedembodiment although not shown or described. Thus, the descriptions ofthese additional embodiments are merely exemplary and not all-inclusivenor exclusive. Moreover, it should be appreciated that the features,components, elements and functionalities of the various embodiments maybe combined or altered to achieve a desired percutaneous stimulationsystem without departing from the spirit and scope of the presentinvention.

The described invention can reduce lead placement and testing procedureduration when placing one or more self-anchoring leads. Specifically,placement and testing times are reduced in comparison to prior artsystems by reducing the number of percutaneous insertions required(e.g., the insertion of a needle for test stimulation and a separateneedle for lead deployment or a system in which multiple percutaneousneedles/tubes/catheters are inserted to increase the size of thepercutaneous entrance and allow the lead to be inserted). Thus, incontrast to prior systems requiring multiple insertions and/or separateleads to deliver stimulation, the present system allows for greatermanipulation of the introducer system, particularly along its axiallength (i.e., the depth to which the needle is inserted and repositionedwithout deploying the lead anchor. Also, while some prior systems reliedon a self-anchoring lead made from a flexible coil having a distalanchor electrically and mechanically integrated within the electrode,the present system marks a further improvements to thefracture-resistance of the flexible, helical coils by protecting themfrom stress and metal fatigue during the insertion procedure (inaddition to the migration-resistant and infection-resistant qualities ofsuch flexible coiled or helical structures).

A non-limiting example of the present system includes an introducing andtesting system which reduces the number of percutaneous insertionsrequired and/or enables the goals of introducing, testing, and/or leaddeployment to be achieved with a minimal number of insertions (e.g., asfew as one (a single) insertion). Specifically, the stimulation testingand lead insertion/deployment may all be incorporated into a systemwhich may require as few as one (a single) percutaneous insertion,injection, or placement. The invention described here eliminates theseissues while still allowing for a migration resistant coiled lead with adistal anchor to be deployed.

The introducing device may include an outer or delivery sheath. An innersheath, stylet, or introducing member may be disposed within the outersheath. The inner sheath is configured to engage and/or manipulate animplantable electrode. In an example, the delivery sheath may comprise astimulation probe having an uninsulated portion at or near a distal endof the delivery sheath. The outer sheath may be coupled to a powersource or stimulation signal generating circuitry at a proximal end. Aclinician may control application of the stimulation signal to a tissueregion via the outer sheath. The clinician may probe tissue regions toapply a stimulation signal and observe a response to the stimulationsignal (e.g., a nerve response, a muscle response, etc.) or a lack ofresponse. When the clinician observes a desired response at a targettissue region (e.g., region where desired response is observed), theclinician may facilitate deployment of an electrode. For instance, theclinician may press, twist, or otherwise manipulate amechanical/hydraulic/electrical mechanism (or other appropriatemechanism) to cause the inner sheath and an electrode lead to translatewith respect to the distal end of the outer sheath. When an anchorregion (e.g., a terminal portion having a bend, barb, hook, etc.) of theelectrode is at least partially deployed, the clinician may retract theinner sheath and/or outer sheath while the electrode remains in or nearthe desired tissue region. The anchor region may be uninsulated to allowfor a stimulation signal to be delivered. In another aspect, theelectrode may include a microlead or an insulated area that may extendfrom the anchor region and may connect to a stimulation source. It isnoted that the stimulation source may be wearable, implantable, orvarious other appropriate types of stimulation sources, such as thosedisclosed in U.S. Patent Publication No. 20150073496 A1, which isincorporated by reference in its entirety.

Turning now to FIGS. 1 and 2A through 2D, one embodiment of leadintroducing system 100 is shown, with particular emphasis on how thelead is deployed. While the same system is shown in each of thesefigures, certain reference elements have been omitted in certain viewsin an effort to highlight specific aspects of the view shown in thatfigure. The introducing device 100 includes an inner sheath 102, animplantable electrode 130, and an outer sheath 150. The outer sheath 150may comprise a hollow tube or needle having an outer sheath cavity 154.In an embodiment, the outer sheath 150 may be a 19-gauge needle with aninner diameter of approximately 0.5-1.0 mm and an outer diameter ofapproximately 0.8-1.20 mm. In one embodiment, the outer sheath 150 mayhave an inner diameter of approximately 0.85 mm and outer diameter ofapproximately 1.03 mm. Outer sheath 150 may be between approximately100-150 mm in length. In an embodiment, the outer sheath 150 may have alength of approximately 125 mm.

The outer sheath 150 may be constructed from an echogenic, i.e., highlyvisible under ultrasound conditions, material to facilitate use of thesystem 100. Such materials include, but are not necessarily limited to,a polymer, metal, stainless steel, or a combination of two or morematerials. Additionally or alternatively, the shape of the outer sheathitself may be constructed so as to be effectively echogenic. Stillfurther, only certain portions of the introducer system, including butnot necessarily limited to the outer sheath, could have echogenicfeatures (either by way of materials or construction/shape).

The inner sheath 102 is disposed within the outer sheath 150 so as toallow it to protrude from the cavity 154, as shown and described inFIGS. 2A-2D below. The inner sheath comprises an inner sheath cavity104. In an embodiment, the inner sheath 102 may be a 21-gauge needlewith an inner diameter of approximately 0.5-0.9 mm and an outer diameterof approximately 0.7-1.10 mm. In one embodiment, the inner sheath 102may have an inner diameter of approximately 0.61 mm and outer diameterof approximately 0.8 mm.

The inner sheath 102 comprises any appropriate material including, butnot limited to, any appropriate material, including, but not limited to,a polymer, metal, stainless steel, or a combination of two or morematerials. The implantable electrode 130 is at least partially disposedwithin the cavity 104, as well as along a portion of the interior of theinner sheath 102 so as to allow the electrode 130 to move freelyrelative to this interior surface. In an alternative embodimentdescribed in more detail below, the electrode 130 has a coiled structurewith a centrally disposed axial void space that may receive a styletthat serves as a deployment mechansism and/or structure support prior todeployment of electrode 130. In this alternative embodiment, the styletengages the electrode along its axial void but once again allows for theindependent movement of the stylet relative to the electrode undercertain conditions.

Implantable electrode 130 may comprise a microlead 138 disposed withinat least the interior of outer sheath 150. The electrode 130 itself isdeployed through the cavity 104. The microlead 138 may extend from adistal lead anchor 134 and couples to (e.g., removably or irremovably) astimulation signal generator (not shown). The lead anchor 134 maycomprise an uninsulated portion of the electrode 130 that may be bent,hooked, barbed, or the like. As such, lead anchor 134 may deliverstimulation signals both during and after it has been positioned anddeployed. Further, the electrode 130—including the lead 138 and anchor134—may have any combination of the following on part or all of thecomponents: a monopolar nature; a helical and/or open-coiled structurewith a central void that could receive a stylet; and/or multiple strandsof an electrically conductive material wound together and electricallyin parallel relative to one another.

While the particular disclosure of implantable electrode 130contemplates a subcomponent including a microlead 138 and anchor 134,the more general term “lead” can refer to the stimulation apparatus fromits distal anchor all the way to its proximal connection to a stimulusgenerating unit, including portions that may be jacketed, covered, orcoated by insulating material. In contrast, the general term “electrode”may refer to the exposed, electrically conductive portion of the leadthat is inserted into the body to deliver stimulation.

As shown in FIGS. 1 and 2A, the lead anchor 134 may comprise a bent orhooked portion such that a portion of the lead anchor may wrap around orhook around a distal end 108 of the inner sheath 102. When the leadanchor 134 is not deployed, a portion of the lead anchor 134 may bedisposed in an area 120 between the inner sheath 102 and the outersheath 150. The lead anchor 134 may be comprised of any appropriatematerial, including, but not limited to a polymer, a metal, stainlesssteel, or a combination or two or more thereof. An one aspect, the leadanchor 134 may be electrically and mechanically integral with theelectrode through which stimulation is delivered.

FIGS. 2A through 2C and 2D illustrate the relative movement of the innersheath 102 and outer sheath 150. Upon insertion (FIG. 2A and inset (A)of FIG. 2D), these elements move in concert with one another. To deploythe electrode 130, the relative movement of one of the sheaths isapprehended or reversed, causing the electrode to protrude out of cavity154. Once the inner sheath 102 is extended far enough out of cavity 154(FIG. 2C and inset (D) of FIG. 2D), the distal anchor 134 is releasedfrom area 120 and embeds itself in the tissue proximate to theintroducer system 100. The inner and outer sheaths are retracted(together or separately), and the electrode is released therefrom (e.g.,temporarily disconnecting the electrode from the pulse generator toslide the sheaths off, physically removing the sheaths, etc.). As seenin FIG. 2E and as will be described in greater detail below, thedeployment may also involve rotational movement (indicated by thearrows) that allows the anchor to be released and to protrude through achannel or slit of the sheaths.

The outer sheath 150 has an inner diameter that is sufficiently largerthan an outer diameter of the inner sheath 102 so as to create the area120 where a portion of the lead anchor 134 is disposed prior todeployment of the electrode 130. A distal end 158 of the outer sheath150 may be uninsulated while a body 162 of the outer sheath 150 may beinsulated, so as to allow current to be delivered to the distal end 158while the body 162 of the outer sheath 150 does not directly stimulatetissue. It is noted that the area of the uninsulated distal end 158 maybe about equal to an area of the uninsulated portion of the lead anchor(e.g., the electrode) 134 to ensure equivalent testing of stimulation ona target tissue region.

The present invention includes a lead insertion/deployment system andtest stimulation system may be combined into a single system whereinelectrode(s) (incorporated into the needle) are utilized for thedelivery of test stimulation currents. In various non-limiting examples,the external portion of the system is insulated or non-conductive exceptfor one or more portion that is un-insulated and conductive to serve asa stimulating test electrode contact. The stimulating test electrodecontact may be mechanically integrated with the outer needle with theelectrode contact located appropriately, such as at a location whichprovides information to guide correct/optimal positioning of the leadprior to its deployment.

The characteristics of the electrode contact may be designed torepresent, predict, or otherwise provide information regarding theperformance of the lead prior to lead deployment, particularly withrespect to size, shape, material, and surface area. For example, byselecting mechanical and/or electrical properties similar to orrepresentative of the lead electrode contact (e.g., similar impedance,contact materials such as stainless steel, and/or similar surface areasuch as 10 mm²)), the characteristics of the test electrode contact willrepresent the anticipated performance of the lead. The test electrodeposition should be at or near the distal end (or tip) of the introducerneedle such that, when the self-anchoring lead is deployed, the leadremains in close proximity to the location occupied by the teststimulation electrode. Alternatively, multiple electrode contacts may beadvantageously spaced along the needle/sheath (e.g., 1 mm-30 mmintervals, preferably 1 mm) such that test stimulation can be deliveredfrom one or more different test electrode contacts on the same needle,thereby allowing the optimal location for stimulation to be identifiedwhile minimizing or eliminating the need to move and reposition the leadintroducing system during the test stimulation/optimal locationidentification procedure. In such multiple test electrodeconfigurations, test stimulation is delivered from multiple locationsfrom one percutaneous insertion to determine the optimal deploymentlocation for a self-anchoring, infection and migration resistant coiledlead with a distal anchor/electrode.

In an embodiment, the lead anchor 134 may fold over the inner sheath102, e.g., at the distal end 108 of the inner sheath 102, so the leadanchor 134 may be contained in the area 120 between the inner sheath 102and the outer sheath 150 prior to deployment of the lead anchor, e.g.,during testing and/or the locating a target tissue region. Thiscontainment of the lead anchor 134 may allow for testing of tissuestimulation and reposition of a location of delivery prior to deploymentof the lead anchor 134, among other potential uses.

Test stimulation used for lead deployment may be accomplished by passingelectrical current into the surrounding tissue through the needlesand/or sheaths or test electrode(s) situated on an exterior surface(s)thereof. The test electrodes could be formed via openings in aninsulating polymeric jacket situated around the outer sheath 150 (or, insome embodiments, the inner sheath 102) with current passing through thesheath itself for stimulation, or the electrodes could be discretelyformed elements (possibly including discrete wiring for stimulationsignals). Other arrangements contemplate the use of a conductive coating(making appropriate contact with a pulse generator/signal source)disposed along selected exterior surfaces of one or both sheaths.Alternatively, test stimulation can be accomplished through an exposedportion of the electrode 130 itself. In this arrangement, a portion ofthe distal end of the lead protrudes through cavity 154 (and, in someembodiments, cavity 104), while the lead itself remains in anon-deployed state (i.e., in some embodiments, the anchor portion 134 isstill held firmly within area 120). In either instance, after insertionof the introducer device 100 into the tissue, test stimulation isdelivered prior to the deployment and anchoring of the lead in thattissue.

In FIGS. 3A and 3B, the exposed exterior portion or portions of theneedle 150 include multiple test electrodes 152. Test electrodes 152 maybe positioned at intervals along the length of the needle and/orradially at different locations around the circumference of the needle.While some embodiments may include only a single test electrode, the useof multiple electrodes is advantageous because it enables teststimulation at multiple locations in the tissue with as few as possible(e.g., single) insertions and/or injections and/or movements of theneedle, ensuring the procedure is simple and time efficient, whileavoiding the need to reposition the introducer or lead to evaluate otherpotential electrode locations. While the outer sheath 150 is depicted,the inner sheath (if used) may incorporate similar test electrodes. Inthis arrangement, it will be understood that the inner sheath must besufficiently expelled through the cavity 154 in order to expose the testelectrodes 152 to tissue intended for test stimulation, although in thisarrangement the inner sheath should not be expelled so far outside ofthe outer sheath as to cause the anchoring system 134 to become embeddedin the tissue. Electrodes 152 may be positioned in regular or irregularintervals, along a straight linear line or around portions or theentirety of the circumference of the needle. Although multipleelectrodes are shown, some embodiments may require only a single testelectrode. Also, while the electrodes are depicting as running along thelength of the needle, it may be possible to position the electrodes atdifferent positions around the circumference, or even to use a fullycircumferential electrode at one or more locations.

In another embodiment, the electrode (e.g., the simulated electrodesurrounded by insulative material or the conducive electrode on thesurface of the needle and/or sheath) may be repositionable (e.g.,through a pulling or twisting control mechanism in the needle hub orhandle) and may be used to test stimulation in multiple locations,offering the advantage that multiple locations of test stimulation maybe applied in a single insertion without deploying the lead. In anotherembodiment, a coating (e.g., insulative, polymeric) may be partially orcompletely applied to any surfaces (e.g., conductive, metallic) incontact with the lead and/or the external needle (e.g., interior ofinner needle or outer needle, exterior of inner needle), so as toprevent current discharge from undesired locations and enabling properstimulation for use to identify locations for lead deployment.

In all embodiments, a lubricious coating (e.g., a hydrophobic coatingsuch as polytetrafluoroethylene) and/or a biocompatible lubricant (e.g.,a silicon based material) lubricant be applied along any portion of theneedle and/or along other moving parts within the system 100 to improveease of manipulation of the introducer components (e.g., the sheathsand/or needles) as directed by the clinician. This arrangement enablesease of movement and helps to avoid the need for larger diameters in theintroducer in the design, as well as minimizing the risk of impropermovement of the needles which may damage the lead and improving thesimplicity of the lead placement procedure to eliminate the occurrenceof technical difficulties for the clinician.

In FIG. 3C (which is rotated in comparison to the views shown in FIGS.2A through 3B so as to eliminate a view of the edge of the distal end ofthe needle), a slit 160 is provided along a length of the outer needle150. While shown as running all the way to the tip 154 of the sheath 150along its underside, it will be understood that the channel 160 may beformed in a line or pattern along only a portion of the sheath 150 or,it may include a series of slits, channels, or apertures to accommodatethe lead anchor (not shown in FIG. 3C) as described herein. Further, thechannel, slits, or apertures may be formed along any axis of the sheath,rather than being limited to only the top or underside. Optional testelectrodes 152 may also be positioned proximate to the slit facilitatepositioning of the introducer system. After appropriate test stimulationand positioning, the electrode is rotated relative to the outer sheath150 so as to allow the anchor (not shown) to release and deploy into thetissue. The clinician will ensure that this deployment corresponds tothe optimal test electrode(s) 152 as identified during the teststimulation procedure.

In an aspect, the introducing device 100 may be designed to incorporatetwo needles with a minimal size increase over a one needle design, forexample. As shown in FIG. 4, the outer sheath 150 may have a groove 156along at least a portion of its inner surface 158, forming a space forthe lead anchor (not shown in FIG. 4). This design may allow the leadanchor 134 to fit and/or translate into the groove 156. In an aspect,the groove 156 may allow for a smaller diameter of the outer sheath 150as additional room, e.g., area 120, for the lead anchor 134 is reduced.

In an embodiment as shown in FIG. 5, the diameter of the sheaths may bereduced by having a slot 110 on the inner sheath 102, such that the leadanchor 134 can re-enter the inner sheath 102 after its deployment,thereby allowing the outer sheath 150 to be situated close to, or evenin direct contact with the inner sheath 102. The distal end 108 of theinner sheath 102 comprising the slot 110 and the lead anchor 134 thatextends beyond the inner sheath 102 and re-enters into the slot 110 maybe situated external to the outer sheath 150, so that the remainder ofthe inner sheath 150 may remain in direct contact or nearly directcontact with the outer sheath 150. Further, the inner sheath 102 may becomprised of any appropriate material, including, but not limited to,thin-walled polymers, metals, stainless steel, or a combination thereof.A thinner material for the inner sheath 102 may allow the outer sheath150 to have a smaller diameter and still contain the inner sheath 102 ora portion thereof.

Applying test stimulation (e.g., stimulation performed prior to orduring lead deployment and/or repositioning) that is representative ofstimulation by the lead itself is advantageous because it allowsclinicians to quickly and simply identify the desired location for leaddeployment through a minimal number of needle insertions, avoiding theneed to reposition the needle(s) and/or lead. Minimizing needleinsertions minimizes the risks and discomfort for the patient and,generally, provides a more reliable method for lead deployment incomparison to previous systems.

Although shown as having a tapered edge that is similar to that of outersheath 150, the distal end of the inner sheath 102 does not have to be acylinder; rather it may be any appropriate size and shape. For example,the distal end 108 may be beveled, cylindrical, partially-cylindrical,notched, rectangular, or the like.

In an embodiment as shown in FIG. 6, the functions of the inner sheath602 may be embodied/replaced by a shaft with a curved arm or end portion656. The curved end can be locked across the inner sheath cavity 504 tohold the bent anchor of the lead 634. When ready for deployment, theinner sheath 602 may be pushed forward, engaging the anchor 634 toposition or otherwise dispose the anchor 634 in the tissue. The innersheath 602 can be rotated to the side and withdrawn into the innersheath cavity 504. The curved arm 656 may then rest along the inner wallof the inner sheath 602 or may be otherwise positioned to allow theinner sheath 602 to be withdrawn while leaving the deployed anchor 634in place.

The lead insertion/deployment and test stimulation systems may becombined into a single system in which a lead deployment mechanism iscontained within a single sheath/needle/tube which contains the lead.This example may consist of a stylet which runs through and/or alongsidethe lead within an introducing needle/sheath. As seen in FIG. 7, thestylet 170 may provide the flexible coiled lead with increasedstiffness, allowing the lead to be manipulated within the needle. Inthis example, the anchor of the lead may be contained entirely withinthe introducing needle and/or be secured such that the system may berepositioned without deploying the anchor until such a time asdeployment of the lead and anchor is desired. A release mechanism mayengage the electrode/lead along one or any number of points, with arelease mechanism accessible to the clinician to allow for selectiveretraction of the stylet 170 after the system 100 is positionedappropriately.

This stylet system solves the problem of selectively deploying aself-anchoring lead, creating a selectively self-anchoring leaddeploying system with significant advantages over the prior artincluding a lead that has design advantages such as infectionresistance, migration resistance, fracture resistance, selectivelyself-anchoring mechanism, an anchor which is integrated with theelectrode contact(s) such that stimulation can be delivered through theanchor (further ensuring correct positioning of the contact ismaintained as desired), a design and/or fabrication that enables thelead to remain in the desired location within the tissue while in usefor therapy and/or trial/testing and then enable easy, safe,comfortable, and/or reliable withdrawal/removal when desired. Althoughthe stylet or core may be used in an embodiment with a singlesheath/needle/tube, it can also be utilized in combination with a systemof multiple sheaths wherein one or more sheaths are used forhousing/securing the lead and/or for delivering test stimulation and thestylet/core is used to position/deploy the self-anchoring lead in theoptimal location. Non-limiting examples of methods for lead and/oranchor deployment are described in other sections.

In another embodiment the lead and/or electrode anchor may be held inplace (e.g., within one of the needles and/or sheaths) by a balloon(e.g., an inflatable and/or deflatable or expandable and/or compressiblesubstance or device), whereby manipulation (e.g., inflation, deflation,compression) enables the lead to be released, exposed, and/or deployed(e.g., exposure of lead anchor, release of outer sheath needle enablingit to be withdrawn and the lead deployed). The use of a balloon isadvantageous because it prevents premature movement of the lead, sheathand/or needle, stabilizes the lead and/or anchor to protect the lead ortip from damage, and can enable full deployment of the electrode leadanchor (e.g., into surrounding tissue) to secure the lead and preventmovement of the lead (e.g., following deployment or during retraction ofthe needle.

Further, as a non-limiting example, the uninsulated lead tip may bemanufactured or bent in the shape of an anchor, but loaded into theneedle and held in a straight position as seen in FIG. 8. In this case,the lead tip anchor 134 will be designed and manufactured to return toits original shape during lead deployment. When exposed by retraction ofthe external needle 150 or advancement with the inner sheath or stylet170 (as indicated by the various arrows in FIG. 8), the lead tip maybend to anchor into nearby tissue.

A straight lead tip may also be pushed by a balloon or sheath or pulledby a hook into an anchored position (e.g., bent). In an alternativeembodiment, the lead may be composed, coated, or framed by a shapememory alloy (e.g., nickel-titanium alloy) that returns to a desiredshape upon exposure a change in temperature or to the heat of the humanbody. Lead fracture rate may also be reduced by eliminating the need forstorage of the lead with a bent tip, which will eliminate excess forcesplaced on the lead tip anchor during storage and lead placement.

Once testing has identified the desired position for placement of thelead anchor 134, the inner sheath 102 may be pushed forward relative tothe distal end 158 of the outer sheath 150. In an aspect, the innersheath 102 may be pushed forward until the lead anchor 134 is exposed.The inner sheath 102 and outer sheath 150 may slide relative to eachother to expose part or all of the lead anchor 134. In an embodiment,the lead anchor 134 may move approximately 0.1-0.3 mm from its originallocation. In an embodiment, the lead anchor 134 may move approximately0.2 mm from its original location. In an aspect, the outer sheath 150may be pulled back/retracted until the lead anchor 134 is exposed. Thisaspect for the lead anchor 134 to remain stationary through theplacement process, i.e., at the same position relative to the targettissue (e.g., nerve or nerve fiber(s)) and the non-target tissue. Oncethe lead anchor 134 is exposed from the inner sheath 102 and/or theouter sheath 150, the microlead 138 may be deployed and/or anchored tothe target tissue region. Further, the inner sheath 102 and outer sheath150 may also slide to recover a lead anchor 134 and/or microlead 138,such as to reposition the lead closer to or father from a target tissueregion, e.g., a nerve. In an embodiment, the lead 134 may be exposedwithout deploying. In an embodiment, the lead 134 may be initiallyexposed without deploying and then may be deployed at a later stage. Inan embodiment, the lead 134 may be repositioned multiple times.

It can be clinically useful to limit the difference in location betweenthe final lead deployment site and the test stimulation site such thatthe clinical results of stimulation with the final, deployed lead inplace are substantially equivalent to the results of stimulation duringtest stimulation in the optimal location. In at least one embodiment,the distal end 158 of the outer sheath 150 may comprise a generallydifferent bevel (e.g., a deeper bevel or greater angle of bevel) thanthat of the distal end 108 of the inner sheath 102. This may allow thelead anchor 134 to be deployed without pushing the inner sheath 102beyond the end of the outer sheath 150. The bevels of the distal end 158of the outer sheath 150 and the distal end 108 of the inner sheath 102may be angled in directly or partially opposed directions. Thisparticular arrangement may limit how far the inner sheath 102 must bemanipulated (e.g., pushed, etc.) to allow for deployment of the leadanchor 134. In an embodiment, the outer sheath 150 bevel may be moreshallow or at less of an angle as compared to the inner sheath 102bevel.

FIG. 9A illustrates various beveled tips for either of the sheaths 102,150. In an embodiment, a short bevel or true short bevel with a steeperangle may be used as the inner sheath 102 bevel with a standard bevel ora longer bevel (with more gradual, less steep angle) on the outer sheath150 bevel. This can provide significant advantages, such as allowingless movement of the needles/tubes relative to each other during leaddeployment and allowing test stimulation to effectively predict theresults of stimulation with the final (e.g., deployed) lead whichdelivers stimulation through the distal self-anchoring component of thelead.

The present invention includes a system which combines test stimulationand lead insertion/deployment into a single system. A non-limitingexample wherein the lead insertion/deployment system and teststimulation system may be combined into a single system is one in whicha self-anchoring lead is utilized for the delivery of test stimulationcurrents prior to being selectively deployed in the optimal locationidentified by test stimulation. In this example, the self-anchoring leadconsists of one or more anchors located on the distal portion of thelead which are also the active/electrode portions of the lead (e.g., thestimulation current is delivered through the anchoring portion of thelead), which enables test stimulation delivered through the lead (andtherefore through the lead anchor) to be optimally similar to finalstimulation when the self-anchoring lead is deployed, as the anchorwhich secures the position of the lead in the tissue is itselfdelivering the stimulation. This example may consist of the leadanchor/active electrode portion being secured relative to the insertionneedle such that all or a portion of the non-insulated portion of thelead (e.g., the electrode/anchor through which current is delivered tothe targeted tissue) is exposed to the stimulation target tissue. Inthis example, the anchor of the lead may be secured such that the systemmay be repositioned without deploying the anchor until such a time asdeployment of the lead and anchor is desired.

In summary, the securing of the lead may be embodied by the following: asheath which secures the extreme (i.e., distal) end of the anchor whileleaving a portion of the lead (e.g., the bend of the anchor) exposed tothe tissue; a wrap or sheath which secures the anchor of the lead andmay be opened/broken to deploy the lead anchor; and/ containing the endof the lead within the insertion needle with a portion of the anchor(e.g., the bend of the anchor) extended beyond the proximal side of theneedle bevel. These examples provide a system for the delivery of teststimulation within the same system used for leadintroduction/deployment, eliminating the need for separate systems whilestill allowing the lead to be positioned/re-positioned as necessaryuntil final deployment. This embodiment may be usefully combined withother portions of the invention described here such that the goals ofintroducing, testing, and/or lead deployment can be achieved with aminimal number of insertions (e.g., as few as one (a single) insertion).

The introducing device may enable multiple or additional lead locationsor potential lead locations to be tested and evaluated prior todeploying the lead. In an aspect, the introducing device may enable theintroducer to be advanced, withdrawn, or otherwise repositioned (e.g.,moved forward or backward or in other directions) without deploying thelead. The introducing device may enable a system and a method foradvancing, withdrawing, or otherwise repositioning (e.g., in any3-dimensional tissue volume) a selectively self-anchoring lead. Anon-limiting example of a non-selectively self-anchoring lead (e.g., alead that was self-anchoring but not selectively self-anchoring) mayinclude a lead with a distal electrode that may be integratedmechanically and electrically with a distal anchoring mechanism.

In previous technology, non-selectively self-anchoring leads wouldcommonly experience unwanted deployment withdrawal or repositioning ofthe introducer. That is, if non-selectively self-anchoring leads andintroducer systems were advanced beyond the optimal location (e.g.,undesirably advanced too far, too close to the target nerve orstructure, etc.), the non-selectively self-anchoring leads would stilldeploy at a suboptimal location because the lead could self-anchor andself-deploy when the introducer was withdrawn. Previously, non-selectiveself-anchoring leads and delivery systems could not be retracted,withdrawn, or otherwise moved backward without lead deployment. Thepresent introducing device allows for use selective self-anchoring leadsand delivery systems, including the associated devices and technology.

The introducing device includes a selectively self-anchoring lead andinsertion system that may locate an optimum location for a lead to bedeployed. In this manner, the lead is deployed only when desired, and itmay be easily and/or atraumatically withdrawn when desired (e.g., whenpain relief or restoration of function is no longer needed).

The introducing device provides a redirectable or steerable introducerand lead system. Previous devices did not teach a technology that couldbe steered in one direction and then redirected and steered in another(i.e., different) direction without deploying a self-anchoring lead. Theintroducing device enables one to steer a selectively self-anchoringlead and introducer system in multiple directions and redirect the leadand introducer system without deploying the lead.

The introducing device may also enable and facilitate the use of imagingguidance, such as ultrasound-guidance and/or fluoroscopic guidance,during the lead placement, testing, and/or lead repositioning procedure.Visualization of the position, orientation, and/or trajectory of theintroducer and/or lead is critical for successful lead placement by theclinician.

Manufacturing the introducer system, and particularly the outer sheath150 and/or lead 130, to incorporate easily visualized/identified indiciasimplifies the lead placement procedure, reduces risk for the patient,improves reliability of lead placement, and avoids improper or prematuredeployment of the self-anchoring lead. The tip of the lead and/or othersections or lengths of the lead may be manufactured (e.g., coated,labeled, textured, etc) with alternative materials that are easilydetected under medical imaging, as this is important to improve ease oflead placement and detection of the device with imaging As anon-limiting example, the lead tip or portions or segments of the leadmay be textured to increase echogenicity, improving visualization underultrasound. In another embodiment, the tightly coiled and twistedstructure of the multi-stranded lead wire may be braided, coiled orwoven at the tip to increase reflectivity and echogenicity. Further,texturizing smooth metal or the addition of a textured conductivecoating would enable better detection under ultrasound while enablingelectrical stimulation. In another embodiment, the lead tip may betextured to improve echogenicity, but coated with a conductive materialthat results in a smooth surface that reduces potential for tissuedamage, patient discomfort and enables easier removal from tissue.Alternatively, in another non-limiting example, the needle or a lengthof the tip may be coated, textured or marked to improve visualizationunder ultrasound. Modifications to the tip to increase echogenicity thatincrease surface area may also reduce the electrode impedance of theneedle tip, enabling selective stimulation of the desired neuraltargets. In another embodiment, the two introducer needles or sheathsmay be labeled, coated or etched in banded pattern to mark length alongthe shaft. In such an embodiment, the bands or labels may be used toassist in deployment of the lead at the desired depth, used to guidemovement of the needles or sheaths in relation to the other, and used todifferentiate these and facilitate lead placement under ultrasoundimaging Further, the markings of the sheaths or needles could be used asa scale for distance and depth during lead placement procedures that isimportant for estimating distances e.g., the distance of a nearby targetor non-target structure and depth of insertion. In another embodiment,the introducer needle(s) or sheath(s) may be composed of materials whichto enable magnetization (e.g., ferritic stainless steel, or non-metallicmagnet) for detection with advanced ultrasound needle localizationsystems.

The position, orientation, and/or trajectory of the introducer and/orlead is important for successful lead placement by the clinician, forexample under x-ray imaging, such as fluoroscope, x-ray or CT.Modifications to the existing introducer system and/or lead through theaddition of radiopaque markers can simplify the lead placementprocedure, reduce risk for the patient, and improve reliability of leadplacement, allowing visualization of lead placement and avoidingimproper or premature deployment of the self-anchoring lead.Additionally, the lead tip or needle may be coated with a radiopaque orradiodense substance (e.g., barium, radiopaque polymer) to improvevisualization under x-ray imaging (e.g., fluoroscopy, x-ray, CT).Radiodense metals, e.g., platinum, gold, tantalum, or for example, aradiopaque conductive polymer, may be applied to the lead tip permittingvisualization under x-ray imaging, while still enabling current flow forstimulation. As a non-limiting example, a portion of the lead, includingthe uninsulated or insulated wire, may be coated or manufactured with aradiopaque material, such as with a titanium, tungsten, barium sulfate,and zirconium oxide, to enable better detection under fluoroscopy orx-ray. This will enable visualization on x-ray of potential fragments toenable better detection of lead fragments left behind after leadremoval. In one embodiment, the coating may be sprayed or electroplatedon the lead tip. In another non-limiting example, radiodense markers mayalso be applied in bands or segments along the length of the needleand/or lead to be used for identification of position and depth of leador needle in the tissue under x-ray imaging In another embodiment, theradiopaque markers along the length of the lead could be used to assesslead depth and track lead migration during therapy, making it easier toconfirm lead placement stability for continuous therapy. As anothernon-limiting example, the inner and/or outer sheaths may be labeled ormarked with radiopaque materials to assist with lead placement underfluoroscopy and visualization of needle depth, monitoring the respectivelocation of needles or sheaths, and proper deployment and anchoring ofthe lead.

The introducing device may also enable selectively self-anchoring leadand insertion system that may place a selectively self-anchoring lead inanatomical locations that are capable of movement, including but notlimited to limbs, joints, back, neck, head, abdomen, torso, face, andextremities, foster tissue ingrowth that seals the skin exit site, andprevent the lead from positioning in and out of the skin, which canfurther minimize infection risk.

The introducing device may also avoid interference with normal functionof the body or body parts, rehabilitation, or return to normal function.As a non-limiting example, the introducing device may avoid interferencewith use of a joint (e.g., prior to, during, and/or following jointrepair or replacement surgery) and avoid interference with use of ajoint (e.g., including the original joint, repaired joint, and/orreplacement joint) during post-op rehabilitation and daily activities.

Some embodiments may employ different designs to provide for differentexposure of leads. In one embodiment, the opening at the distal end ofthe outer sheath has a beveled or slanted edge, as as seen in FIG. 9A,so that rotating the outer sheath uncovers or recovers an exposed anchorlead. This may allow a clinician to expose part or all of an anchorlead, e.g., part of a barb or tine. In an embodiment, stops could beadded into predetermined locations to allow for ease in exposing aportion of a lead without deploying the entire lead. In an embodiment, aclinician could apply a rotation or a sliding type mechanism to deploypart or all of the lead. In an embodiment, the introducing device couldemploy a rotation technique to only partially expose the lead withoutfully deploying it and a sliding sheath could fully expose and deploythe lead, e.g., in a channel and/or lock design.

In one embodiment as shown in FIG. 10, the inner sheath 802 may includean inclined portion 824 that may facilitate deployment when the sheath802 is withdrawn. This may alter (e.g., reduce) the possibility of alead 834 being compressed or otherwise held within the sheath 802. Forinstance, it may reduce a possibility of the hooked, tined, barbedportion of a lead from being held or attached to the inner sheath 802.In another aspect, the inclined portion 824 may alter (e.g., improve)the ability to anchor the lead 834 at a desired location. The use of asmall-diameter self-anchoring coiled or helical lead enables theduration of the lead placement and stimulation testing procedures to beminimized, limits the number of percutaneous insertions required,decreases risk to the patient, enables efficient positioning andre-positioning of the lead for stimulation testing and lead deployment,enables clinicians to position and deploy the lead correctly andoptimally with minimal or no additional training, and decreases the timerequired to form electrical connections for testing.

Test stimulation through the introducer system requires electricalcurrent be passed to the stimulating electrode and/or lead tip from theexternal stimulator. The present invention is novel and advantageousbecause it allows the introducer system to be coupled to the externalstimulator used by the patient, ensuring the responses achieved duringtest stimulation (e.g., in clinic, hospital, etc) are representative ofthe responses to be expected and/or achieved during therapy (e.g.,typical home use by the patient) and further avoids the need toreprogram the stimulator between test stimulation and home-goingstimulation.

The introducing device may be removably coupled with a stimulatorthrough the use of a lead connector. The stimulator may be poweredthrough a battery embedded within the stimulator itself or an attachedelectrode.

The battery may be any appropriate size that allows for continuousdelivery of therapy for consistent pain relief to the user. Further, thestimulator may be wirelessly programmable and controllable. In anembodiment, the stimulator may be wired. In an embodiment, thestimulator and introducing device may have custom wireless interfacesfor the clinician and/or patient.

In an aspect shown in FIG. 11, the proximal end 512 of the introducingdevice 500 may include a connector plug 560 that may be coupled to apower source and/or current source (not shown). Current may be passedfrom the power source through the connection plug 560 and to the outersheath 550. The current may pass through the outer sheath 550 and beapplied to a tissue region at the distal end 558 of the outer sheath550.

The present invention includes designs to facilitate the use of the leadfor testing, a non-limiting example being a connector which canelectrically connect the proximal end of the lead to an externalstimulator via a wire quickly and effectively in a useful way (e.g.,strong/stable mechanical and/or electrical connection) and which canreduce the duration of the procedure. Being able to easily remove theconnector also can reduces procedure time, as upon lead deployment inthe prior art, the introducer system must be withdrawn over the lead,and a connector would stop this from happening and would need to beremoved as the introducer needle/sheath cannot be withdrawn over itwithout first disconnecting the lead. Although a simple connector (e.g.,a commercial alligator clip) could be used, such a connector can bedifficult to use in an operative setting with an extremely smalldiameter coiled lead. Clinicians or staff may have difficulty connectingthe tiny end of the wire to a typical/mechanical electrical connector. Anon-limiting example that addresses these issues is a custom connectorconsisting of a funnel which the end of the lead can easily be insertedinto. The funnel guides the lead wire into the connector area, whereteeth, loops, or surfaces which are spring-loaded can be manipulated bythe user via levers or buttons to clamp onto and create an electricalconnection with the lead. This connector could have a wire and plugattached with allows for connection with an external stimulator.

A lead connector may be designed to couple to the percutaneous leadeasily. In a non-limiting example, the lead 934 may be inserted throughan aperture or slot 952 in the lead connector 956, and the lead cablemay go through partially or completely therethrough. The aperture mayinclude a funnel shape where the lead 934 is inserted to enable easyinsertion into the aperture, as indicated by the arrows in FIGS. 12A and12B. In another non-limiting example, the lead connector 956 may becomposed of two or more components with the lead placed between and/orwithin the components, and the components may be secured together (e.g.,slid together, snapped in place, twisted/screwed onto one another, etc.)to couple to the lead. In some embodiments, the lead connector mayenable easy one-handed insertion and coupling of the lead to the systemwhile remaining mechanically and electrically secure and prevents thepatient from decoupling the lead (or electrode) intentionally orunintentionally.

The lead may be coupled to the lead connector electrically andmechanically. The mechanism by which the lead may be coupledmechanically to the lead connector may be separate or the same as themechanism by which the lead is coupled electrically to the leadconnector. The user may couple the lead to the lead connector using acomponent including, but not limited to, a knob, button, switch, ordial.

The lead connector may be decoupled from the lead, and may allow thelead to be reconnected to the lead connector at a different point alongthe lead (e.g., closer to or farther away from the stimulating portionof the lead or electrode). In a non-limiting example, the lead connectormay include a lock to prevent the patient from disconnecting the lead.The lock may be opened using, for example (but not limited to), a key, atool (e.g., torque wrench), a code (e.g., combination) or without atool. In another non-limiting example, the lead connector may minimizeor eliminate damages or changes to the lead's structure, enabling thelead to remain sufficiently intact to generally reduce the risk of thelead fracturing or breaking and enable current flow through the entirelead. In another non-limiting example, a lead connector may be attachedto the lead prior to or after insertion of an introducer system,enabling stimulation through the lead tip during the lead placementprocedure. In one embodiment, the connector may be attached to the leadby dropping the lead into a slot or hole on the block and closing a flapwhich implements an insulation displacement connection (e.g., cuttingthrough the insulative material aside to form a connection with theconductive lead wire). This lead connector may improve the speed andease of lead connection because it can be attached without the use oftools (e.g., no wire cutters, scissors, and screwdrivers). For example,in this embodiment, the lead may be placed into a slot in a leadconnector block and secured using a lockable, reversible one-handedmechanism to displace the insulation on the lead body. The insulationdisplacement mechanism inside the lead connector may also cut the leaddistal to the electrical connection. Once the connection has been madeand the excess lead is trimmed, a lock (e.g., sliding, twisting, buttonpress) may ensure that the flap on the block cannot be reopenedaccidentally. This feature prevents loss of connection between the leadconnector and lead, which would result in loss of therapeutic benefit.The lead connector may mate with another lead connector (e.g., lead orplug to the stimulator) to complete the circuit from the stimulator tothe lead tip electrode.

In one embodiment, the connection between the two lead connectors may bemagnetic. In this case, the shape of the lead connectors will preventimproper alignment of the lead connector (e.g., lead connectors thatonly fit together in one orientation). The magnetic connection may beused for both temporary and permanent stimulation delivery (e.g., duringlead placement procedure or during patient's home use of the therapy).After obtaining proper lead placement location, the lead connector blockmay be removed and replaced following removal of the introducer systemneedle(s) and sheath(s). In one embodiment, the connection may bedeactivated by pressing or sliding open the slot that contains the lead.In this example, the lead connector block may be removed or cut offprior to removal of the introducer and then quickly re-attached to amore proximal location on the lead. Following removal of the introducer,the lead may be placed in the slot and connected with a one-touchmechanism (e.g., pressing, sliding) and then the lead connector may beattached to the stimulator cable.

The magnetic connection may act as a quick-release connection that willprevent accidental lead (or electrode) dislodgement due to a pulled leadand/or lead. Instead of transferring force to the lead exit site andlead, any forces on the lead will be discharged due to the breaking ofthe magnetic connection between the lead and lead connector block. Ifdesired by the clinician, a permanent connection may be made by lockingthe two-connector pieces together using a press button lock (or anyother suitable lock). In addition to mating with the lead connectorblock, in another embodiment, the magnetic cable connector for thestimulator may also mate with an identical version of the lead connectorblock, which is connected to the test stimulator via a cable. In anotherembodiment, the magnetic cable connector originating from the stimulatormay be bifurcated to connect with multiple lead connector blocks (e.g.,to enable stimulation of two leads with one stimulator).

The present invention may reduce lead placement procedure discomfort bylimiting the diameter of the percutaneous system. Resistance toinsertion through skin or tissue skin may cause additional pressure tobe placed on a patient's skin and/or the device, leading to potentialdiscomfort (e.g., pain or bruising from the pressure of insertion orfrom multiple failed attempts to insert needles) and/or damage or strainon the device (e.g., damage to lead or introducer, lead deploymentmechanism failure). Reducing the resistance to insertion may beaccomplished by limiting the diameter of the introducer system,designing or manufacturing the needle to be sharper (e.g., sharper edgesof heel and/or additional bevels), or coating the surface (e.g.,exterior shaft) of the needle(s). Modifying the bevel shape or sharpnessof the needle(s) in the introducer system (e.g. by the addition ofmultiple bevels during needle manufacture or grinding or shaping theneedles) may make insertion easier (e.g., requiring less force) andensure that the lead placement procedure is more comfortable for thepatient. Multiple bevels and increased needle sharpness are advantageousbecause these minimize risk to patient, enable reliable insertion, andenable insertion that avoids unnecessary pressure on the lead or device.In another embodiment, a coating may be partially or completely appliedalong surfaces of the introducer needle(s) to reduce resistance toinsertion through tissue (e.g., polymeric coating that glides throughtissue easier). In one embodiment, the coating may be hydrophobic (e.g.,polytetrafluoroethylene, silicon rubber), hydrophilic (e.g,polyvinylpyrolidone, polyurethanes, polyacrylic acid, polyethyleneoxide), or liquid-impregnated to improve ease of insertion andmaneuverability within tissue by reducing friction between skin ortissue and the needle. Modifications of the exterior of the needles thatminimize insertion force required by clinicians (e.g., enabling leadplacement by clinicians) and that do not produce a substantial increasein outer diameter will ensure that selective lead deployment may beperformed through minimally invasive approach, using a minimal number ofinsertions and further minimizing risk and discomfort for the patient.

One way to limit and/or minimize the diameter of the system is throughthe use of a needle/sheath with a portion along the inner wall of saidneedle/sheath removed such that space for the lead anchor is allowed.Examples of such configurations are illustrated in FIG. 9B. The portionof the wall N of the needle/sheath 150 is removed/made thinadvantageously such that the lead anchor 134 can be contained (e.g.,1-10 mm of the wall along the length of the needle starting from theproximal end of the bevel, preferentially 5 mm, with a width sufficientto allow the anchor to be contained (e.g., 0.1-0.5 mm, preferentially0.2 mm), but the mechanical strength of the needle is minimallyimpacted. In a system consisting of two needles/sheaths, this could alsobe realized by removing some of the inner needle's outer wall (not shownin FIG. 9B) in a similar fashion, or by doing both such that some of theouter needle and some of the inner needle walls are removed to form acomplete slot for the lead anchor to be contained within.

Another example illustrated in FIG. 9B is to use a plastic inner tube Pthat is stiff enough to allow for deployment, but flexible enough thatthe outer anchor hook (not shown in the perspective views) can press inthe plastic sheath's end, allowing the outer needle to be just largerthan the inner tube and to completely contain the un-deployed lead. Theflexible plastic sheath would also have to be flexible enough that itcould be withdrawn over the lead without catching. Avoiding having thelead catch within an inner tube would be an important issue in thesediameter limiting solutions where the inner needle may lead little spacearound the lead, which could lead to an excess of friction. Anon-limiting example of a solution for this would be the use of abiocompatible lubricant applied between the parts that must moverelative to each other, such as a silicon based (or other appropriate)lubricant

With reference to FIGS. 9C and 9D, embodiments of this invention have aslot or window S ground, cut, or otherwise produced in the sheath/needle102 such that the end of the anchor of the self-anchoring lead 134 canre-enter the lumen of the needle/sheath, allowing a second sheath/needleor containment mechanism to be positioned over the portion of the anchorwhich re-enters the lumen of the needle, thereby securing the lead tothe testing/introducing system until such a time as it is desired thatthe lead be deployed. Desirably, this embodiment of the invention can becombined with one or more of the other examples described, including butnot limited to delivering stimulation through the distal anchor of theself-anchoring lead and/or the use of one or more contact electrodes inthe outer sheath used for delivery of test stimulation. Note that inFIG. 9C, the system 100 is shown in various stages of its assembly, withinset (a) showing only the inner sheath, inset (b) showing the sheath150 and lead/anchor 134, and inset (c) showing the inner sheath 102,lead anchor 134, and outer sheath 150.

Reducing the outer diameter of the system is desirable as this limitsthe discomfort experienced by the patient during the procedure. In theexample in which a sheath over a needle is used to secure the leadanchor of the self-anchoring coiled lead in place duringplacement/testing/repositioning, a tight fit of the outer sheath overthe inner needle, which would both limit the outer diameter and bettersecure the lead anchor, could be accomplished by using a sheath materialthat could be shrunk, for example by application of heat or other meansof causing the sheath tubing diameter to contract. This can also easethe manufacturing and assembly burden of this system, as a tightlyfitting sheath would not have to be threaded over the inner needle andthe lead anchor. The larger diameter outer sheath could easily be slidinto position and then shrunk to provide a tight fit.

Desirably limiting the outer diameter of the system which is insertedpercutaneously or through the skin may be embodied such that pain and/ordiscomfort during insertion, stimulation testing, and/or deployment of aself-anchoring migration-resistant lead is minimized may bepreferentially embodied by utilizing thin-walled needle(s) or sheath(s)to contain the lead during placement/testing/deployment. The use of oneor more needles or sheaths of an appropriate material (e.g., metal,plastic) with a wall thickness that provides adequate lumen space forcontainment of the lead, minimizes the outer diameter of the system, andprovides sufficient resistance to bending and/or other forces to whichsuch a system is subjected during lead placement and testing proceduresis desirable and advantageous. The preferred embodiment of the describedinvention utilizes one or more thin-walled needles/sheaths as describedin combination with one or more of the examples and embodimentsdiscussed which also enable the invention to minimize the duration ofthe lead placement and stimulation testing procedures, limit the numberof percutaneous insertions required, decrease risk to the patient,enable efficient positioning and re-positioning of the lead forstimulation testing and lead deployment, enable clinicians to positionand deploy the lead correctly and optimally with minimal or noadditional training, and decrease the time required to form electricalconnections for testing.

A close fitting sheath over a needle may pose potential problems forlead deployment, for example the sheath may adhere to the surface of theneedle more strongly than anticipated such that movement of the sheathover the needle is prevented or requires such force that the device iseither unsafe or not user friendly and can additionally cause a delay orextension of the procedure. A non-limiting example of overcoming thisproblem is to apply a lubricant between the sheath and the needle suchthat sliding of the sheath over the needle is enhanced or requires lessor minimal force. This lubricant could be based on a silicon jelly, butalso could be realized of other appropriate materials. Anothernon-limiting example of a way to overcome this problem is to have amechanism by which the sheath can be split open. This can beaccomplished by having a thin wire embedded in the sheath which can bepulled upon during lead deployment and which causes the sheath to splitopen allowing the lead anchor to release. These aspects of the inventioncan beneficially be combined with other embodiments of the inventiondescribed.

Another embodiment of an aspect of the present invention to overcome thepotential problem of inappropriate adhesion of components to one anotheris described in a non-limiting example as the use of a manufacturingmethod wherein a placeholder(s) is used during manufacture of various ofthe close-fitting components (e.g., a placeholder such as a solid metalwire preferentially the slightly larger than the diameter of the leadused during the manufacture/fitting of various components designed tosecure the anchor of the lead (e.g., an outer sheath with or without aslot or section removed or ground out specifically to contain the leadanchor)). This is advantageous as it allows the final components to fittogether tightly/securely, but prevents overly tight fitting such thatdeployment and/or positioning and/or testing is impeded or hindered.

The present invention may prevent/reduce user mistakes and mishapsduring lead placement and stimulation testing by allowing for one-handedlead placement and deployment. For example, the lead deploymentmechanism(s) can be manipulated with one hand such that the other handis not required to cause the lead to deploy. Such an embodiment isadvantageous as it both reduces the difficulty for the clinician toutilize the system and allows the clinician to use the other(non-deploying) hand for another purpose, for example to manipulate anultrasound probe during lead deployment such that the position of thelead can be observed. This can be advantageous as it can be used toreassure the clinician in real time that the distal anchor of theself-anchoring lead maintains the desired location during leaddeployment and/or withdrawal of the testing/introducing system. Asnon-limiting examples, the preferred embodiment of a lead deploymentmechanism can consist of a lever(s), button(s), gear(s), slider(s), pushbutton(s), twisting knob(s), handle(s) with gripping surfaces forpulling or pressing on, handles/levers which squeeze together and/orother means of mechanically and/or electrically actuating the deployingcomponent(s). Examples of embodiments of the deploying component(s)(e.g., an outer sheath and/or an inner stylet or core) are described inother sections, and one or more of these may be beneficially combinedwith one or more of the lead deployment mechanisms such that theclinician can easily and effectively control the deployment of theself-anchoring lead.

In one embodiment of the invention, the placement and repositioning ofthe lead is aided by design elements which enhance the controllabilityor the ease with which the clinician can handle the system duringpercutaneous placement, withdrawal, and/or repositioning of the systembefore, during, and/or after stimulation testing and lead deployment.Such an embodiment may limit the procedure time, thereby providingsignificant benefit to both the patient and the clinician. Anon-limiting example of such an embodiment is the application ofergonomic, gripping, textured, and/or other tactile features which canbe located on the proximal end of the needle/system and/or on thedeployment mechanism(s) to ease the placement of the lead through theskin and tissue of the patient, as seen in FIG. 13. Such an embodimentcan provide significant benefit to patients with tough or thick skin, asthe clinician may otherwise have difficult applying the necessarypressure to quickly insert the system through the skin at the desiredlocation.

FIGS. 14A and 14B show embodiments of the introducing devices 400, 500.In an aspect as shown in FIG. 14A, the introducing device 400 includes aproximal end 412 having a body 414 with a lock 416. The body 414 may becomprised of any appropriate material, including polymers, metals,stainless steel, or a combination of two or more thereof. The lock 416may be any appropriate type of lock or stepper, including, but notlimited to, a lever, trigger, plunger, button, wheel, switch, threadedmember, or the like. When engaged, the lock 416 may prevent the innersheath from advancing or moving at all. This may occur through the useof a threaded system, locks, steppers, etc. By releasing the lock 416through pushing, pulling, twisting, or any other appropriate mechanism,the inner sheath may disengage from the lock system and can advanceforward, e.g., out of the outer sheath 450. As the inner sheathadvances, a lead may be deployed. The lock 416 may be comprised of anyappropriate material, including polymers, metals, stainless steel, or acombination of two or more thereof. The lock 416 may be comprised of thesame material as the body 414 or they may be comprised of differentmaterials. The body 414 include a loop 418 and a grip 422 configured toengage with a clinician's finger(s) during use. The loop 418 may beengaged with the lock 416, and when engaged, may allow for the movementof the inner sheath out of the outer sheath 450.

The grip 422 may be comprised of any appropriate material, includingpolymers, metals, stainless steel, or a combination of two or morethereof. The grip 422 may be designed to support the clinician'sfingers, and therefore may be etched or have a rubberized or comfortservice for improved traction and comfort of the user.

In an embodiment, the body 414 may include several loops configured toengage with a clinician's fingers during use, e.g., the thumb, and thepointer and ring fingers, or for a different user, the thumb, thepointer and the middle fingers. In an aspect, the body 414 may notinclude any loops.

Lead deployment may also be initiated through a lock or stepper on theproximal end 512 of the introducing device 500, as seen in FIGS. 14B and14E (with the latter generally showing device 500 along with arrowsindicating the anticipated range of motion). By releasing the lock orstepper, the inner sheath 502 could be advanced by pushing or by use ofa lever, button, wheel, switch, threaded members, or the like. The innersheath 502 may have locks or steppers to prevent the inner sheath 502from deploying too far. The end of the inner sheath 502 may be open soit can be withdrawn over the deployed lead anchor 534 and potentially amicrolead.The system helps to prevent user mistakes and/or mishapsduring lead placement and stimulation testing of a self-anchoring lead,while reducing or limiting procedure duration is one in which thepositioning of the system can be maintained securely throughout theprocedure regardless of the depth and which the lead andintroducing/insertion/testing system has been inserted. Prior art relieson the resistance of the tissue to maintain the position of theinsertion system and self-anchoring lead during testing procedures,raising concerns when the system is placed insufficiently deep in thetissue to allow for the tissue to prevent movement of the system.Non-limiting examples of embodiments which maintain the introducingsystem position throughout testing and/or lead deployment are describedin the following sections such that the various embodiments can provideadditional significant benefit with combined with one or more of theother embodiments/examples described throughout the inventiondescription

As seen in FIGS. 14C and 14D, the system, and more specifically theneedle 150, is inserted into the target tissue/through the skin. Theneedle is mechanically secured to a component X which is, in turn, ableto be secured/fastened to the body/skin of the patient, by way of anadhesive Y as one example. The component is secured to both the systemand the patient's body such that the system is securely held in placerelative to the patient until such a time that the clinician determinesthe system is to be repositioned and/or removed. The component mayconnect to the system via any appropriate mechanical connection whichcan be secured and/or removed with minimal expenditure of time andeffort (e.g., a clamp, lock, twisting, or other securing mechanism).Additionally, the component may connect to the patient's body via anyappropriate mechanical connection which limits discomfort to the patientand can be secured and/or removed with minimal expenditure of time andeffort (e.g., tape, bandage, gel, hydrogel, or other securing mechanismcompatible with temporary use on skin). The component can be secured toboth the patient and the system such that movement of the systemrelative to the patient's body is minimized during test stimulationprocedures and/or lead deployment.

In this non-limiting example, a component such as the one describedabove which mechanically mates the system for the introduction/insertionof the self-anchoring lead and the delivery of test stimulation with thepatient's body is implemented such that the component can be freelyrotated relative to the patient's body while locked in position relativeto the system until the desired locking position is determined.Alternatively, the component may be locked relative to the patient'sbody while allowing free rotation/positioning of the system prior tolocking in the final positioning. Such a component can also allow thepositional locking/securement to be released as necessary for systemrepositioning or removal.

The component X described above mechanically mates the system for theintroduction/insertion of the self-anchoring lead and the delivery oftest stimulation with the patient's body is implemented such that thecomponent is secured in place to the patient's body, and the componentincorporates a mechanism which allows the angle of the leadinsertion/stimulation testing/lead deployment system to be adjusted andlocked into position as desired. Such a component can also allow thepositional locking/securement to be released as necessary for systemrepositioning or removal.

The present system includes designs to objectively reposition thepercutaneous system. A potential problem with delivering teststimulation via a system wherein the anchor of the lead is partially orfully contained is that the lead may inadvertently become deployed bymoving the inner and/or outer needle and/or other method of deployingthe lead in an unintended fashion or relative distance (e.g., the leadis advanced further than intended or at an unintended time). A system bywhich the inner and outer needle (or other deployment mechanisms such asa stylet) relative positions can be locked, stopped, or visualizedduring insertion, testing, and/or deployment is one example of a way toreduce this risk. One embodiment of this solution is to have a series ofstops in the proximal portion of the deployment system which allow theneedles to be positioned relative to each other by twisting, pushing,clicking, rolling, sliding, or other means of control with a lever,locking mechanism, or other means.

This non-limiting example of an embodiment of the invention which allowsfor objective repositioning of the percutaneous system consists ofmechanical and/or visual markings which display the relative positionsof the percutaneous introducing system and the lead and/or a styletand/or an inner sheath/positioning mechanism. Such markings may makeknown the position of the lead relative to the a position in theintroducer (e.g., distance of the distal end of the lead from the distalend of the introducing sheath) and/or the position of the end of theintroducing system in the tissue/body (e.g., the depth distal end of theintroducer system and/or the angle relative to the skin at theinsertion/entry site). An alternative or complementary markingembodiment may include clearly marked positions (e.g., markings fordeployed, locked, and/or other desirable system and/or lead positions).Such an invention may preferably combine these aspects of theembodiment, allowing the depth and angle of the introducer system andthe lead relative to each other and/or the skin/insertion site to bereadily discernible. Such an embodiment allows for objectiverepositioning of the percutaneous system, and may be incorporated withone or more other examples discussed in this disclosure such that theduration and the difficulty of placing a helical, migration andinfection resistant lead in an optimal location is reduced or limited.It may comprise a plurality of arc-shaped channels positioned orthogonalto one another. One or more screw, clip, or spring-loaded pins cooperatewithin the channels (possibly including slots or other predeterminedpoints along the arc or arcs) to fix the position of the angle androtation of the introducer needle relative to the surface of thepatient's skin (i.e., the site of injection for the needle).

The present invention includes designs to objectively reposition thepercutaneous system. A potential problem with delivering teststimulation via a system wherein the anchor of the lead is partially orfully contained is that the lead may inadvertently become deployed bymoving the inner and/or outer needle and/or other method of deployingthe lead in an unintended fashion or relative distance (e.g., the leadis advanced further than intended or at an unintended time). Oneembodiment of this solution is to have a series of stops in the proximalportion of the deployment system which allow the needles to bepositioned relative to each other by twisting, pushing, clicking,rolling, sliding, or other means of control with a lever, lockingmechanism, or other means. Such an embodiment may allow for the lead tobe moved into several different positions such as, but not limited to, alocked/secure position for insertion, a partially deployed position fortesting, a withdrawn position for re-positioning, and a deployedposition. Such an embodiment allows for objective repositioning of thepercutaneous system, and may be incorporated with one or more otherexamples discussed in this disclosure such that the duration and thedifficulty of placing a helical, migration and infection resistant leadin an optimal location is reduced or limited.

In the non-limiting example of concentric needles or sheaths, amechanism is needed to control the movement of the needles and sheathswith respect to each other and the surrounding tissue, ensuring properlocation of lead deployment and avoiding damage to the lead. Selectivelead deployment may be accomplished by sliding the outer needle toexpose the bevel of the inner needle and the tip of the lead and aretraction of the needles to position the lead tip or anchor into thenearby tissue. However, in this non-limiting example, an apparatus tocontrol distance of needle movement is critical for precise leadplacement and to ensure that the needles do not move or slide inrelation to each other prior to or after the deployment of the lead toprevent shearing, fracturing or bending the lead or lead tip.

In order to achieve this level of control, a spacer or place-holdingmechanism S as shown in FIGS. 15A and 15B may be used. These spacerslock the two needles together during insertion through the skin by theclinician and then enable deployment of the lead at a desired location.In one embodiment, the spacer may be composed of a partial or completecylinder and located between the hubs of the inner and outer needles. Insuch an embodiment the spacer may be removable, with threads on the endsthat enable the spacer to lock onto the hubs of each needle (forexample, the spacer may be removed by twisting the spacer past thethreads on the needle hubs and sliding the spacer off). In anotherembodiment, the spacer may remain in place and collapse in order topermit retraction of the external needle. For example, in thisembodiment, twisting or pressing a button on the spacer (as indicated bythe arrows) would enable the spacer to be condensed, allowing fordirected retraction of the external needle.

In another non-limiting example, the needle hub of the external needleor internal needle may be retracted a specified distance into the handleof the introducer. In another non-limiting example, a component of theintroducer handle may be twisted to retract any of the needles, sheathsor leads a specified distance. This would permit controlled retractionof the needle and enable correct placement of leads. In one embodiment,the handle to control the retraction and movement of needles may beergonomically designed with smooth contours to fit in the hand of theclinician and buttons or sliders to enable single hand operation of theintroducer system. Single handed operation further will enable properlead placement, for example, allowing the clinician to visualize thetarget with ultrasound with one hand while advancing, retracting orrepositioning the introducer system and then deploying the lead with onehand. Additionally, the handle of the introducer could be marked toillustrate the direction or side of the needle where the lead will bedeployed to further assist the clinician with proper placement of lead.

In a non-limiting example of an introducer with multiple stimulationelectrodes, the components of or the entire system could be retracted tothe desired location of effective test stimulation, the external needleretracted and the lead tip deployed. Here, the lead may be deployed atany location along the length of the external test needle without havingto redirect the needle. A slit or opening along the length of theexternal needle (also as described above) would permit the lead to berepositioned without having to move the exterior needle. In thisembodiment, the lead may be repositioned with an inner sheath or needlethat enables the lead to be repositioned inside the needle and thendeployed at any depth along the needle.

A non-limiting example is an embodiment in which multiple contacts couldbe positioned on the introducer at specific intervals so that there mayonly need to be one needle insertion and one repositioning of theinsertion/testing system prior to lead deployment. In a non-limitingexample, contacts are spaced (e.g. 1 mm) (+/−) on the outer needle. Theneedle may be inserted to Y mm (e.g. 5 mm) from the nerve. Teststimulation can be delivered from each contact individually or incombination as desired or needed, for example starting with the mostdistal contact. If stimulation at the Z^(th) (e.g. 4^(th)) contactprovides the optimal response, the clinician can then withdraw theintroducer system Z mm (e.g. 4 mm) and deploy the lead (with or withouttesting again—both or either of which could be desirable in variousscenarios, making it potentially advantageous to provide the option tothe clinician).

In another non-limiting example, there could also be software toaccelerate, expedite, or automate this process, including the process ofdelivering test stimulation at multiple contacts sequentially. In anon-limiting example, once information such as calibration point(s) or arange(s) (e.g., a range of physiologic responses to a range ofstimulation intensities, a range of distances from the target ornon-target tissue(s), etc.) is known from testing the first (or other)contact(s), the software could enable testing to be progressively fasteror more expeditious for subsequent contacts. There could be advantagesto not having it completely automated (e.g., ensuring stimulation doesnot produce unwanted responses such as pain, discomfort, or unwantedmuscle contractions).

The present invention may prevent/reduce user mistakes and mishapsduring lead placement and stimulation testing by incorporating patientfeedback automatically during stimulation testing via a patientcontrolled testing system, simplified parameter testing procedures,and/or a system which requires only patient feedback to operate. Thiscan advantageously reduce both the time of the testing procedures and/orcan limit the number of position changes the system may require beforelocating the optimal or desired lead deployment position.

A non-limiting example which incorporates patient feedback intostimulation testing is one in which test stimulation is controlled bythe patient. A controller (e.g., hand-held remote, tablet, smartphone,or other appropriate interface) is handled by the patient which may becapable of delivering stimulation currents directly to the teststimulation system via a cable or may control a stimulus generator viawired and/or wireless technology (e.g., Bluetooth, RadioFrequency). Inturn the generator is mechanically and/or electrically connected to thetest stimulation system such that electrical stimulation currents can bedelivered through the system to the target tissue. The patientcontroller may allow the patient to adjust one or more parameters (e.g.,pulsewidth, amplitude, frequency, and/or waveform of the electricalcurrent/signal/test stimulation) such that the patient is able to obtainthe desired physiological response (e.g., paresthesias, musclecontractions, and/or pain relief). Alternatively, such a controller maybe handled by a clinician with adjustments being made based on theresults of the test stimulation (e.g., based on verbal feedback from thepatient, visualization of contraction directly and/or via ultrasound,and/or clinical experience). The non-limiting examples described heremay advantageously be combined with one or more of theexamples/embodiments of the described invention.

Where stimulation testing is controlled by the patient, one aspect ofthe invention (reducing overall procedure duration) may be hindered bystimulation testing controls and/or parameters which are complicatedand/or provide patients (or clinicians) with more options than necessaryto test and identify the optimal or desired lead deployment location.These risks may be minimized by simplifying the methods and/or thecontrols for adjusting parameters during stimulation testing. FIG. 16indicates a number of parameters (i.e., pulsewidth and amplitude of thestimulation) and how these parameters might be adjusted by the patientcontroller. As represented by the linear arrows in each of the insets(a) through (c) of FIG. 16, only a limited number ofinputs/buttons/knobs/controls (e.g., 1 to 5 function features, and morepreferably 3). These inputs correspond to the ability to increase and/ordecrease the parameters as shown in FIG. 16. In one embodiment, a singlebutton increases one or more parameters (e.g., pulse duration,amplitude, frequency, and/or a combination of parameters), anotherbutton decreases one or more parameters, and a third button enables teststimulation to be turned on and off. The control can be advantageouslycalibrated or designed specifically for a given type or style ofstimulation (e.g., high or low frequency, causing or avoiding musclecontraction vs. sensory nerve fiber activation, etc.) prior to useduring the placement and testing procedures.

Additionally or alternatively, patient feedback may be incorporated intothe testing procedures through the use of software/programming thatadjusts test stimulation parameters based on input/feedback from thepatient and/or the clinician. Such adjustments enable the testingprocedure duratin to be minimized, while simultaneously avoiding anypotential uncertainty regarding stimulation parameter adjustments. Inthis non-limiting embodiment, the patient and/or clinician obtainsfeedback using a graphical interface mechanism, such as a controller ortablet GUI as shown in FIG. 17, that allows information regarding theresults of test stimulation to be relayed to or communicated with thestimulus generator. Such a controller could include, for example, ainputs by which sensations (e.g., paresthesias), pains, and/orcontraction intensity may be communicated by the patient to theclinician, as well as the location of such sensations, pain, orcontractions on the patient's body. For example, tablet GUI display animage representative of a portion or all of the patient's body and whichallows the patient to select/highlight/draw or other means of makingknown the areas which in which stimulation is felt/seen/results in someoutcome. Software determines appropriate adjustments to the teststimulus parameters and/or recommends to the clinician how to re-director reposition the system to a new test location and/or where to deploythe lead (e.g., in the current location, in the new test location,etc.). Such a program, system, and/or method may be combined with one ormore of the other embodiments of this invention such that thecombination is advantageous for the purposes of the invention.

An exemplary stimulator may be able to provide at least the followingparameters: amplitude of 0.2-20 mA; pulse duration of 10-200 μs; andfrequency of 5-100 Hz. The stimulator may be connected to software forwireless clinician programming of the therapy, software and hardware fora wireless patient controller, and firmware and hardware for a miniaturebody-mounted stimulator. This arrangement allows for the clinician andpatient to view and adjust treatment parameters without having tointerface with the stimulator directly. This can prevent a patient fromhaving to remove clothing, etc., to reach the stimulator during use. Inan embodiment, the stimulator may communicate via physical cables,wires, Bluetooth, or other wireless technologies. The present teachingsare not limited to any particular configuration.

The patient controller may also provide a more extensive graphical userinterface including a variety of other options (e.g., profiles specificto a time of day/type of pain/type of anticipated patient activity,access to information on pain management, means for communicating with amedical professional, etc.), thereby making it the primary means ofinitiating and altering the therapy. As with the stimulator, thecontroller communicates via physical wires/cables or wirelessly with thestimulator (or stimulators, if multiple stimulators are included in thesystem) and the optional programmer unit, described below. Thecontroller may be relatively larger than the stimulator, althoughwireless connectivity would allow the user to carry the controller inclothing and/or generally at a convenient distance and location incomparison to the electrode 934 and stimulator. The connections betweenthe controller, stimulator, and introducer system may include any ofthose described herein (e.g., standard wired connections, wirelessconnections—particularly between the controller and the sitmulator,wired connections relying on quick release mechanisms, etc.)

The stimulator allows for adjustment of stimulation intensity bycontrolling stimulation amplitude and pulse duration, preferably with asingle programmable parameter for intensity. Stimulation intensityitself may be determined by multiple parameters, including (but notlimited to) stimulation amplitude and pulse duration. For example,stimulation intensity may be increased by increasing stimulationamplitude, pulse duration, or a combination of the two. Controllingmultiple parameters such as stimulation amplitude and pulse durationusing a single parameter may reduce the complexity of the procedure toprogram stimulation parameters by reducing the number of parameters thatcan be changed from 2 or more to 1. As a non-limiting example, theminimum of the stimulation intensity parameter (e.g., 0) may set thestimulation amplitude and pulse duration to their lowest values (e.g.,0.2 mA and 10 microseconds). As another non-limiting example, increasingthe stimulation intensity parameter may change the stimulationamplitude, the pulse duration, or both.

In yet another embodiment, increasing the stimulation intensityparameter from the minimum value may first increase the stimulationamplitude while keeping the pulse duration at a minimum until themaximum value of the stimulation amplitude (e.g., 20-30 mA) is reached.Then, continuing to increase the stimulation intensity parameter maykeep the stimulation amplitude fixed at the maximum value whileincreasing the pulse duration until the maximum value of the pulseduration is reached. In these embodiments, stimulation intensity issimple to program and may be increased while keeping pulse duration aslow as possible, so as to keep the stimulation charge required toactivate nerve fibers as low as possible and to increase thepatient/clinician's ability to selectively stimulate large diameterfibers over small diameter fibers. In another non-limiting example,increasing the stimulation intensity parameter from the minimum valuemay first increase the stimulation amplitude while keeping stimulationamplitude at a minimum. Then, continuing to increase the stimulationintensity parameter beyond the maximum value of pulse duration (e.g.,200 microseconds) may keep the pulse duration fixed at the maximum valuewhile increasing the amplitude until the maximum value of thestimulation amplitude is reached. In this example, stimulation intensityincreases while keeping stimulation amplitude as low as possible, whichkeeps the power consumption of the pulse as low as possible for a givencharge per pulse.

FIG. 18A is the first example given, keeping pulse duration low. FIG.18B is the second example, keeping stimulation amplitude low.

The introducer system described herein may also reduce the risk ofproblems following lead placement by reducing the risk of lead fracture.This risk reduction results from the shape of the electrode itself, bothin terms of its self-anchoring, migration-and-infection-resistant smalldiameter helix/coils and its distal anchoring system, and from thereduced levels of stress imposed upon the lead during the insertion andtest stimulation process by way of being able to retract and protect theelectrode during insertion and repositioning.

Other advantages include the ability to enable the duration of the leadplacement and stimulation testing procedures to be minimized The systemalso limits the number of percutaneous insertions required, decreasesrisk to the patient, enables efficient positioning and re-positioning ofthe lead for stimulation testing and lead deployment, enables cliniciansto position and deploy the lead correctly and optimally with minimal orno additional training, and decreases the time required to formelectrical connections for testing. As a result, the therapy can bedelivered to patients by clinicians in settings/scenarios that werepreviously burdensome, not practical and/or not possible (e.g., to treatpre-operative, pen-operative, and/or post-operative pain). Thisintroducer also overcomes limitations of previous systems by minimizingor eliminating the need for: a) the insertion via multiple percutaneousdevices; b) re-positioning of the lead ; and/or c) extended periods oftime required for test stimulation and/or lead placement procedures.

One embodiment consists of increasing the strength of the coiled/helicallead, for example by incorporating one or more strands of high tensilestrength materials (such as but not limited to MP35N,nickel-chromium-molybdenum super alloy) into the lead. Adding suchstrand(s) and/or replacing current lead wire strand(s) with suchstrand(s) or wire(s) increases the fracture-resistant capabilities ofthe lead, increasing the utility of self-anchoring, migration andinfection resistant small-diameter coil/helix leads for use inelectrical stimulation systems.

Another non-limiting embodiment consists of improving the strength ofthe lead by adding a new strand/filament within the open core/center ofthe helically coiled lead. In this non-limiting example, the newstrand/filament would not completely fill the opening. There wouldremain a gap between the outside of the new strand/filament and theinside of the coiled wire. Moreover, this new strand/filament would notextend the entire length of the coiled lead. In this non-limitingexample, these two provisions help the lead remain flexible with bothaxial and radial forces during normal use. When the lead is withdrawn,as the coiled wire straightens out, the inner diameter of the coils ofthe lead will reduce and the coiled wire becomes bound to the centralstrand/filament. Thus the lead has a higher tensile strength and reducedflexibility during the removal process compared to the normal useconfiguration. The new strand/filament in the core could be a metal(e.g., 316L or MP35N) or it might be a polymer (e.g., Aramid). Such anembodiment could advantageously combined with other aspects of thedisclosed herein (e.g., the use of stylet proximate to—or even as partof—the strand/filament).

As noted above, the risk of lead fracture before, during and/or afterperipheral nerve stimulation therapy with self-anchoring, migration andinfection resistant small-diameter coiled/helical leads is minimizedbecause the stresses placed upon the lead during the lead placement,testing, and/or repositioning and deployment procedure are limited. Anon-limiting example of an embodiment which leads to such a reduction inmechanical stress is a design which incorporates contouring (e.g.,rounding or smoothing) of the inside edge of the needle/sheath which maycontact the lead where it exits the bore/lumen of the needle/sheath.

Prevention of fracture and/or damage to any portion of the lead and/orself-anchoring electrode tip is critical to ensure maximal therapeuticbenefit and reduce risk of adverse events for patients. The innovative,coiled lead was designed to move with tissue and skin and protectsagainst fracture while in tissue during therapy. However, methods toeliminate other detrimental forces encountered by the lead during leadplacement may further reduce the risk of lead fracture, improving safetyof the system and avoiding need for lead replacement. This may beaccomplished through approaches designed to reduce the force appliedand/or transferred from the needle to the lead and/or anchor tip duringinsertion of the lead and changes to methods for manufacturing of theanchor shape to reduce strain on wires in the lead.

For example, the boundaries of the needles and/or sheaths (e.g., heel,rim, edge, bevel) may be smoothed or rounded off to prevent sharpcontact with a portion of the lead and/or other component of theintroducer (e.g., sheath, balloon, which may be negatively impacted bysharp edges of the needle or sheath). In one non-limiting example,manufacturing and/or fabricating the introducer needle heel with roundedthe edges (e.g., by grinding, sanding or smoothing the surface) wouldeliminate sharp edges that may be pressed against or come into contactwith the lead, which weakens the mechanical or electrical connections inthe lead, thereby reducing the risk of lead fractures. The design anduse of rounded edges in the introducer prevents the occurrence offractures or strains resulting from a lead constrained against a sharpedge (e.g., heel of the needle) during insertion, which may weaken thetensile strength of the lead and result in lead fractures. The lead mayalternatively be manufactured to reduce the likelihood of lead fracturesby reducing the strain placed upon the lead tip during the creation ofthe lead anchor. In the prior art, the anchor was fabricated usinguninsulated lead anchor (e.g., by folding it to produce a sharp bend),creating a point of high strain at the bend (e.g., anchor, hook) in thelead. To prevent this point of greatest strain, the lead anchor may bemanufactured by gradually rolling the lead around a ball or pulley-typesystem to generate a curve-shaped (e.g., rounded) anchor in the leadthat is free of a sharp bend. In another embodiment, the curvedself-anchoring lead tip may be used to secure the lead into tissuefollowing deployment during lead placement. Alternatively, the leadanchor tip may be manufactured in other shapes (e.g., straight, rounded,coil, serpentine), which enable the lead to be deployed and anchored intissue, improving the strength and performance of the wires due tomanufacturing that avoids sharp bends in the lead tip.

The inner and/or outer needles of the present introducer system usefully rounded edge surfaces that may come into contact with the lead.The fully rounded shape is carried through the entire cross sectionalshape (e.g., by maintaining a substantially constant radius) in order toeliminate or reduce risk of lead impingement, which could subsequentlyincrease risk of lead fracture. The use of rounded or approximatelyrounded edges, optionally coupled with elimination of edges or sharppinch points on the lead in the introducer and throughout the insertionprocess, increases the reliability and performance of the lead andimproves the safety profile and safety margin for the patient.

Prior art iterations of cutting edges for needles or other lumens areshown in FIG. 19, which includes exploded inset views at the top. Theseillustrations are also reflective of European Patent No. EP0929330 B1 toGravelee. Generally speaking, angled, cutting edge E2 is disposed at thedistal end of needle/lumen E. In some embodiments, sharp leading portionof the cutting edge may be situated along the inner diameter of thelumen E rather than as shown on its outer circumference. In contrast toother conventional needles having a top edge E3 that substantiallymirrors the bottom edge E2, top trailing edge E4 may be partiallyrounded (i.e., not as sharp as the cutting edge 38) along its innerdiameter edge. This rounded trailing cutting edge E4 allows the tissueto be punctured without a plug of tissue from being cut out by thetrailing cutting edge of the needle which might then be injected into apatient's tissue or into the blood stream and possibly cause adownstream embolus (blockage of a blood vessel) or an abscess.in thisconfiguration, the partially rounded edge E4 of the needle E extendsaround 1% to 60%, and preferably to about 50% of the circumference ofthe needle E. Notably, a substantial portion of the cutting edge of E4is still flattened, presumably to facilitate the cutting action, so thatboth edges E3 and E4 present a potential “pinch point” in the eventneedle E were used as an inner sheath. In both illustrations of FIG. 19,the leading cutting edge E2 makes a curvilinear or an arc shaped cutthrough the tissue, with the resulting curvilinear incision in a bloodvessel sealing and healing much more readily than if a tissue plug hasbeen removed.

As seen in FIG. 20A (including an exploded inset of the trailing edgeR4) through 20C, the introducer system has a more fully rounded edge R4or transition between the inner diameter of the lumen R and the outsidesurface along a portion of the trailing edge R4 of curvilinear openingR6. Lead cutting edge R2 is disposed along the opposing side of openingR6. This attribute is a significant advantage, particularly at the heelor trailing edge of the bevel, where the lead anchor (not shown) is bentor flexed during part of or all of the development, manufacture,assembly, delivery, use, insertion, positioning, and/or repositioning intissue. By rounding this region of the needle (and/or other areas wherethe electrode bends or flexes at an acute angle while potentially makingcontact with an edge surface), the sharpness of the edge is reduced soas to completely eliminate any edge which could, cut, severe, nick ,create an unwanted notch, or otherwise damage or impair the function ofthe lead which can and/or will contact the heel of the bevel. Anotherdesirable attribute of the present invention is that it can combine thebevel with the rounded edge so that it enables insertion of theintroducer and lead into the tissue without risking damage to the leadwhile maintaining a sufficiently sharp (e.g., not blunt) leading edgeand interface enabling it to advance through tissue.

As seen in FIG. 20C, the fully rounded edge can also be reproduced alongany portion of the edge R14 associated with the slot R16 through whichthe distal end of the electrode (not shown) may be restrained. Incontrast, edge R12 could be fully rounded, or it could more closelymimic the sharper cutting edge of leading edge R2. Slot R16 may have asimilar curvilinear shape in comparison to opening R6, although it ispossible to form slot R16 as an elongated, oblong, slit-like, orpolygonal shape situated offset from, parallel to, or orthogonal withthe axis defined by the cylindrical shape associated with needle R.

The fully rounded aspect of the needle or edge which is rounded in theprior art is different from the rounded edge in the present invention.The prior art describes edge E4 as extending only along the innercircumference of the needle, thereby retaining a pinch point (albeit onewith a slight less sharp edge). In contrast, rounded edge R4 thatextends from the inside to the outside of the needle (i.e., to retain asubstantially constant diameter relative to the arc formed by therounded edge), thereby distributing force applied to the electrodeevenly along the entire surface of the edge R4. In another embodiment,the round edge R4 is orthogonal or perpendicular to the circumference ofthe needle (i.e., the edge that extends from the inner to the outerdiameter), thereby encompassing oval shapes whose radius may vary. Inboth instances, edge R4 creates a smooth transition that is devoid ofany pinch points, and the term fully rounded encompasses both constantradius arcs as well as ovals.

As a further example of differences between the prior art and thepresent introducer, the goals of the prior art and the present inventionare different. The prior art is designed to enable insertion into ablood vessel, whereas the introducer described herein intentionallyattempts to avoid contact with blood vessels and, instead, is designedto penetrate tissue proximate to nerves. The prior art is also designedto avoid cutting a plug of tissue, whereas the fully rounded edge isdesigned to avoid or reduce damage to a self-anchoring electrode beforeand during lead placement, testing, re-positioning, and/or deploymentprocedures.

In contrast to prior art, the fully rounded edges or surfaces inlocations contacting or of potential contact with the lead to eliminateor reduce risk of lead damage, which could increase risk of leadfracture. The use of fully rounded edges effectively eliminates edges orsharp edges, increases the reliability and performance of the lead, andimproves the safety profile and safety margin for the patient.

Tuohy needles and modified Tuohy needles known in the art have a dulledbevel to enable catheters to be passed through them more safely. Suchcatheters possess a substantially larger diameter, insofar as they mustaccommodate fluid flow without creating blockages. In contrast, theintroducer system is not designed for catheters and, instead, employs adesirably thin gauge needle with an inner diameter (e.g., lumen) that isonly large enough to accommodate a fine wire lead so as to enable thesystem to penetrate and advance through tissue. As such, Tuohy needlesare incompatible with the design intent of the introducer system, andtheire excessive diameter would create difficulties in accommodating alead without excessive movement and potential damage to the lead.Further, the distal anchor of the lead rests against the heel of thebevel in a way that enables the introducer to maintain the position andlocation of the lead relative to the introducer as it is manipulatedwithin human or animal tissue.

The present system for the percutaneous placement of a small-diametercoiled lead also reduces the risk of accidental lead dislodgement. Thisobject of avoding lead dislodgement is achieved with self-anchoring,migration and infection resistant small-diameter coil/helix leads.Further, these advantages are particularly useful (in comparison toprevious systems) during the initial period of time in which the lead isleft in place within the desired tissue (e.g., in the time period priorto complete encapsulation of the lead within connective tissue, or from1 day to several months of indwelling). Other advantages (possibly inaddition to others noted herein) include the ability to enable theduration of the lead placement and stimulation testing procedures to beminimized; a reduction in the number of percutaneous insertionsrequired; a decrease risk to the patient by enabling efficientpositioning and re-positioning of the lead for stimulation testing andcorrect/optimal lead deployment by clinicians with minimal or noadditional training, as well as by decreasing the time required to formelectrical connections for testing. Therapy may be delivered to patientsby clinicians in settings/scenarios that were previously burdensome, notpractical and/or not possible (e.g., to treat pre-operative,pen-operative, and/or post-operative pain).

In certain embodiments, accidental lead dislodgement is also avoided byrelying on an anchoring mechanism made from a bioabsorbable material(e.g., Poly glycolic acid: Trimethylene carbonate, Polylactic acid, orother appropriate bioabsorbable material with sufficient mechanicalproperties to act as an anchoring mechanism) at least in portions of thelead/electrode. The use of such a bioabsorbable anchor(s) facilitatesfixation of the lead in the tissue, avoiding accidental dislodgement.Use of such an anchor(s) can also be designed such that as the leadbecomes encapsulated/secured by tissue growth, the anchor(s) becomeabsorbed, thereby reducing the risk of fracturing the lead upon removalat the end of the active therapy. Over time, the biosorbable portionsare then accommodated naturally by the body, leaving only thestimulation portions of the lead securely in place.

Monofilaments of material (e.g., similar to dissolving sutures) maysupplement the distal anchor(s), along with any number of optionalbarbs, in order to help with short-term fixation. These filaments and/orbarbs may have varying or consistent geometry, including various shapesand thicknesses that can be made using conventional molding. These tipsmay be attached by integrating mechanically with the lead by a number ofappropriate methods, examples of which include integration within theopen coil of the lead, by overmolding the lead, or by covering theexisting insulation coating of the lead with a secondary extruded layerof bioabsorbable material. Additionally, bioabsorbable tips may beattached to the lead through a hot melt approach (using an absorbablematerial as the adhesive). Such approaches allow the present inventionto enhance short-term fixation and avoid accidental dislodgement whileusing or placing a self-anchoring, migration and infection resistantcoiled/helical lead. These biosorbable aspects may be used alone or,advantageously, in combination with one or more aspects of the presentinvention described elsewhere in this disclosure.

With reference to FIG. 12A, once the lead is placed in the patient, theintroducing device may be disengaged and removed. A proximal portion ofthe lead 934 may then be engaged with a lead connector unit 950 asindicated by the arrow. The lead connector 950 may have an insulationdisplacement connector (IDC) (not shown in FIGS. 12A and 12B) and agroove 952 configured to receive a lead 934. The groove 952 may comprisea contact strip with receiving members (e.g., micro-structure barbs,snaps, magnets, etc.) (not shown) to hold the lead 934 in place.

Another embodiment of the lead connector that eliminates the need for aseparate tool as it can allow for a one-handed push mechanism for theclinician and/or patient is shown in FIG. 12B. The lead (not shown) isreceived in the aperture 952, which may have a conical, funneled, orcylindrical shape terminating in the connection point of the mainhousing of unit 950. The lead connector unit 950 may also include abreak-away connection, e.g., the lead connector end 954 includes amagnet with the opposing end of the lead connector cable end 956 havingan oppositely charged magnet (mated in the embodiment shown in FIG.12B), allowing a clinician, patient, etc., to easily disconnect thecable 958 from the unit 950. This magnetized or other type of connectioncan be integrated anywhere along the body of unit 950. The connectionmechanism also contemplates other removable connection types, includingsnaps, adhesives, clips, Velco®, force fittings, or any otherappropriate means of connection.

Additionally or alternatively, the connector 950 may have a rotatingelement, such as a knob, dial, spool or post 953. The rotating elementmay engage the lead, mechanically and/or electrically, in order toassist in adjusting the tension of the detachable connection havingtension formed by the electrode, the lead connector and the lead. Therotating element may include a predetermined tension release or recoilmechanism that responds to a disconnection force by releasing excesslead that is wound around the element. In the same manner, the leadconnector 950 may accomplish this tension release by slider or othermovement that need not be rotational in nature. As with the detachableaspects of the lead connections, the tension release may occur at aforce that is less than or equal to one-half the force required todislodge or move the electrode from its initial position.

The IDC mechanism may assist in connecting the lead 934 into the groove952 in order to enable the connection between the receiving members andthe lead 934. In this embodiment, the clinician relies on his or herdominant or non-dominant hand to insert and connect the lead. The IDCmechanism may also be capable of stripping any insulation from the lead934 in order to establish better electrical contact between the lead 934and the unit 950/groove 952. The IDC may be formed integral with orseparately attached to the lead connector unit.

Exemplary alternative embodiments of the IDC are depicted in FIGS. 21Aand 21B. IDC 989 shown in FIG. 21A may include a drawer type mechanism990, such as a pivoting disc that rotates relative to pivot point PP andin the pivoting direction indicated by arrow PD, that is insertable intothe body of the IDC and removable therefrom. A slot 952, similar infunction to that described in FIG. 12A, bisects a portion of the disc.Slot 952 has an appropriate shape and size to firmly engages the leadwithin the disc and may include slidable portions, jaws, barbs, or thelike. Disc 990 rotates so that the proximal end of the lead is fullyinside the IDC 989 while the other portion protrudes out of the unit989. Springs, locks, and guiding mechanisms may also be provided toafford better control of disc 990 when in operation.

In another embodiment shown in FIG. 21B, an IDC 1089 may have agenerally cylindrical shape. The IDC 1089 may include an aperture, slotor opening 1990 into which the lead may be inserted (similar to thefunction and features associated with slot 952 above). The IDC 1089 mayinclude an actuating lever AL to twist or rotate the body of IDC 1089relative to the portion containing the slot 1090 (i.e., as indicated bypivot direction arrow PD) so that the lead is secured inside the IDC1089. Barbs (not shown) may be included in the interior of the IDC 1089if necessary to remove insulation from the lead to expose the underlyingwire. Cooperating guides or grooves (not shown) may facilitate to therelative motion of the bodies 1089, 1090, and stops and lockingmechanisms may also be included to prevent accidental motions.

The lead connector 950 may be bifurcated to receive a plurality of leads934. For example, multiple slots or funnels can connect multiple leadsto a single stimulator to enable therapeutic stimulation to be providedto separate parts of the body.

The connection between the lead connector 950 and electrode 934 may bedetachable. The detachability may include, without limitation, magnets,such as insert molded neodymium magnets, that may be formed on theconnector and one or both ends of the lead (if on both ends, thestimulator would also have a detachable connection as described herein).Depending on the manufacturing process, the magnets, and how the magnetsare fitted together, may allow for differentiating the points ofconnections. For example, the lead connector may have a steppedconnection port that fits with a correspondingly stepped connection onone of the lead, as illustrated in FIG. 22A. Alternatively, a circularmagnet may sit on the top of the connector lead, also shown in FIG. 22B.A slight indentation or groove or other releasable force fitting couldbe provided to allow for the experience of a “snap-in” feel.

In addition to or in place of magnets, a spring-loaded fitting could beused. An example of such a fitting is shown in FIG. 22C. The fitting isdescribed generically so that it may be employed on any of thecomponents, although particular utility is expected at the connectionbetween the lead connector 950 and the electrode 934. End A has aninverted Y shape that mates with a corresponding shaped end B.Additional shapes, prongs or members may be included. The outermost armsC move, preferably in a spring-loaded or magnetic fashion, to receiveand release end A (single ended arrows indicate a preferred range ofmotion). Ends A and B may be fitted in the plane parallel to the doublearrow and/or they may be dropped or snapped into place and then releasedin a direction that is different than, preferably includingperpendicular to, the direction of release.

In some embodiments, the lead connector and lead may include adetachable connection configured such that neither the stimulator notthe lead are displaced if unwanted force is applied to them or theirconnection(s). For example, the connection between the lead and thestimulator may be detachable upon application of a predetermined force.The predetermined force may be calculated to generally prevent movementof the electrode once placed in the appropriate position within thepatient.

Alternatively or in addition the lead may itself be detachable (e.g. inthe middle so that it actually is a plurality of leads, e.g., two ormore). The lead may be detachable at any point between the lead and thestimulator, e.g., lead may disconnect at either end. Further still, thepredetermined detachable portion may be between the lead and stimulator,along any portion of the length of the lead. For example, two or moreleads could be selectively attached at a detachment point to disconnectupon application of the predetermined force. Further, while the presentdisclosure notes that the portions are detachable, they may also bere-attachable. This may allow the system to serve as a failsafemechanism to prevent damage and/or injury to the system, components,and/or the patient.

In addition to just safely detaching, the circuitry in the lead (and/orother components, such as the lead connector) may prevent delivery ofunwanted stimulation in the event of a disconnection during stimulation.By way of a non-limiting example, the lead may be a “smart lead” thathas components in addition to a path for electrical conduction thatminimizes the risk of the patient experiencing unwanted stimulation(e.g., minimizes or eliminates the potential for the patient toexperience a shock) when the lead is disconnected unexpectedly duringuse.

All of the above-mentioned connections rely on mated parts. In order toavoid improper installation, each of the mated pairs could be given aunique shape. Sensors or other circuitry could be employed at theconnections points to better enhance the user alert feature describedherein. Such sensors or circuitry could be inherent to the electricalsignal delivering the stimulation, or separate signals could beestablished.

In an embodiment, as shown in FIG. 22D, the connection may be comprise alead connector lead end plug with at least two-prongs or three-prongs ofsteel electrical contract that attract to the magnetic armature of thelead connector end.

The lead may optionally couple with the stimulator (not shown). Thestimulator may comprise a battery (not shown), a programmable memoryunit, and circuitry necessary to deliver the therapeutic stimulationinherent to the system. In an embodiment, the battery may be embeddedwithin the lead connector or another electrode. The battery may be thin,flexible, and powerful. The battery may contain a charge for use of atleast 24 hours to maximize use without charging or replacement. Thestimulator may also contain a graphical user interface to communicatewith the patient and/or clinician. It may contain LED or other visualindicia to communicate actions, errors, or other pertinent informationabout the operation of the stimulation system. The stimulator may allowfor patient and/or clinician adjustments for the operation of thesystem. Additionally, the stimulator may be worn on a patient's bodythereby minimizing cables and making the system easier to wear thanconventional external stimulators. The stimulator may also be waterprooffor ease of all-day wear.

Additionally, the introducing device may be paired with a custom bandagesystem that minimizes the risk of lead dislodgement during use. As shownin FIG. 23, the lead 1034 and lead connector unit 1050 may be protectedand attached to the patient with a custom bandage 1060. The bandage 1060may eliminate the need for a separate tape to secure the lead 934 andlead connector 950. The bandage 1060 may integrate with the leadconnector unit 1050 to allow the clinician and/or patient to easily andconsistently remove and replace the bandage 1060 without fear ofinadvertently pulling the lead and/or otherwise dislodging it. Thebandage 1060 may be comprised of the same film materials used instandard bandages, e.g., aperture or non-apertured films, including, butnot limited to any polymeric material including, but not limited topolyethylene, metallocene catalyzed polyethylene, polypropylene,polyolefin copolymers, and ethylene vinyl acetate copolymers. Thebandage 1060 may also comprise adhesive material. Suitable adhesives mayinclude, but are not limited to, acrylic based, dextrin based, andurethane based adhesives as well as natural and synthetic elastomers.The adhesives may also include amorphous polyolefins including amorphouspolypropylene. In an embodiment, the bandage 1060 may have an adhesiveperimeter 1062 including optional removal tabs 1064. The adhesiveperimeter 1062 may prevent the lead 1034 from being exposed to anyadhesive surfaces and inadvertently being attached to the bandage 1060.The center of the bandage 1060 may include an absorbent pad 1066configured to cover the entry point of the lead 1034 into the patient.The absorbent pad 1066 may be configured to absorb any fluid exiting thelead insertion site, e.g., any kind of liquid (including, withoutlimitation, blood, pus) that may ooze from the lead insertion site. Thesize of the pad 1066 may allow a patient and/or clinician to view thearea around the lead exit site to determine the existence of anyinfections or abnormalities. The absorbent pad 1060 may be surrounded bya clear polyethylene section 1068 of the bandage 1060 that allows forthe clinician and/or patient to be able to better see the placement ofthe bandage 1060. A cutout 1070 in the adhesive perimeter 1062 of thebandage 1060 overlies the lead connector 1050, eliminating gaps in thebandage seal, but allowing for direct contact between a clinician and/orpatient with the lead connector 1050 during the removal/attachmentprocess. During removal, a patient and/or clinician can put his or herfinger over the pad 1066 and the lead connector unit 950 to generallyprevent the lead 934 from pulling the patient's skin. This may beparticularly useful in difficult to reach position on the patient's bodyand on body parts with frequent movement, e.g., arms, legs, back, head,etc.

When applying or changing the bandage 1060 as shown in the FIGS. 24Athrough 24F, a clinician and/or patient may disconnect the leadconnector cable 1056 from the stimulator (not shown) and apply atemporary tape strip 1072 to apply pressure to the lead connector 1056.The clinician and/or patient may apply additional pressure to the leadconnector 1056 while removing the bandage 1060 from the patient. Thesite may then be inspected and cleaned. A new bandage may be applied tothe site, the temporary tape strip 1072 may be removed, and the leadconnector 1050 may be reconnected to the stimulator.

The present teachings are not limited to any specific treatment orindication. The system may apply to any kind of treatment, including,without limitation post-surgical pain patients or any type of painpatients, especially chronic pain patients (e.g. neuropathic pain,headache, and/or back pain patients).

A lead connector unit may include a lead storage mechanism to storeexcess portions of the lead (e.g., while the lead is coupled to the leadconnector). This mechanism may reduce the excess length of lead betweenthe lead connector and the point from which the lead exits the body.This may reduce the risk of the being caught on an object and beingpulled and/or breaking. If the lead is caught, for example, on anexternal object or from a body part, then the excess lead stored on themechanism may be released rather than dislodging or moving the lead fromthe tissue, fracturing the lead (inside or outside the body), and/orpulling the lead out and decoupling from the lead connector. In anon-limiting example, the mechanism may be a spool around which the leadis wound, either manually or automatically (e.g., using a spring). Inanother non-limiting example, the mechanism may be located on theoutside of the lead connector or within the lead connector. In addition,the lead connector may be padded on one or more sides to provide comfortwhile wearing the lead connector.

The lead connector may also be designed to couple to the stimulatoreasily, and may enable connection using a single hand, such as by way ofa magnetic connection as noted herein. It should be understood, however,that while a magnetic connection is described, the connection maybe anymechanical connection in addition to or alternatively to the magneticconnection. The connection may be oriented at various angles withrespect to the surface of the skin. In a non-limiting example, theconnection is oriented generally perpendicular to the skin. In anothernon-limiting example, the connection is generally parallel to thesurface of the skin. In yet another embodiment, the connection may beeasy for the user to make (e.g., does not require great dexterity, maybe connected even without looking at the connectors) and strong enoughto prevent inadvertent disconnection (e.g., due to common body movementsor small forces, etc.) while disconnecting when subjected to strongerforces that may dislodge the lead (e.g., from external objects or bodyparts pulling or tugging on the lead connector or stimulator attached tothe lead connector). The connection may prevent the lead from dislodgingor fracturing by disconnecting the lead connector and lead when the leadis pulled rather than transmitting the force along the lead. In anon-limiting example, the magnetic connectors may be structured suchthat the surrounding magnetic field is reduced and avoids interferingwith objects placed near the magnetic connectors (e.g., credit cards,cell phones).

Further still, the lead may connect directly to the stimulator (i.e.,lead connector may be built into or integrally with the stimulator). Thestimulator may be placed directly over or adjacent to the lead exit siteto protect the exit site. There may be a clear window through which thelead exit site can be monitored for safety (e.g., infections,irritation).

In another non-limiting example, the lead may connect to the leadconnector using a jack and plug, and the jack may be located on the leadand oriented at an angle (such as 90 degrees) to the lead. This jack maybe connected to the plug on the lead connector using a downward force,enabling connection using a single hand. The very small distancesbetween the magnetic armature of the plug and the permanent magnetstructure of the lead connector means that the residual field outsidethe lead connector is very small as shown in FIG. 26.

A cable may attach to the stimulator and stored or organized (e.g.,wound, coiled, wrapped around) to reduce the length of the lead (orlead) that may become caught, for example, on an external object or abody part. In a non-limiting example, the excess cable may be stored ina storage device attached to the cable, on the lead connector, and/or onthe stimulator. In a non-limiting example, the storage device is a spoolaround which the cable may be wound manually or automatically (e.g., viaa spring). In an embodiment, the cable may be coiled or wound around aspool on the stimulator, and forces on the lead cause the cable to beuncoiled from the spool rather than disconnect from the stimulator,transmit the force to the lead connector, and/or cable.

The stimulation system may contain lead that attach to the stimulatoravailable in multiple lengths. In a non-limiting example, the lead withthe shortest length that enables connection between the stimulator andthe lead connector may be selected to reduce the risk of the leadcatching on an object or body part and disconnecting the system,dislodge the lead, and/or fracture the lead.

In some embodiments, the stimulator may enable coordinated stimulationacross two or more stimulators. In the alternative or in addition, thecontroller and/or programmer unit may enable coordinated stimulationacross two or more stimulators. Coordinated stimulation may enablestimulation across multiple stimulators to start and stop in acoordinated manner to avoid asynchronous activation of muscle onopposite sides of the body (e.g., the back or torso), which may causeloss of balance or discomfort. Control over stimulation across multiplestimulators may also prevent synchronized stimulation, for example, toavoid activation of opposing muscles (e.g., biceps and triceps), whichmay cause discomfort. In a non-limiting example, one of the stimulators,controller and/or programmer unit may communicate with other stimulatorsdirectly. In another non-limiting example, each stimulators may beconnected to a central controlling unit, which may be another stimulatoror may be a non-stimulating control unit. In a non-limiting example,communication among stimulators and/or control units (controller orprogrammer unit) may be wireless (e.g., via Bluetooth, Wi-Fi) or wired(e.g., cables).

A battery-operated, body-worn stimulator may generate electrical currentthat may be administered via the lead and/or introducer. In oneembodiment, the stimulator is a small pod (e.g., with rounded contoursand of minimal profile height) that is worn on the body via a gel patchelectrode that serves as the return electrode and is connected with twosnaps that also provide electrical connection. In one embodiment, thestimulator has a minimal user interfaces (e.g., a press buttonstart/stop, LED lights and a speaker or buzzer) to provide criticalfeedback to the patient. For example, the lights may blink or light up(e.g., different colors or different flashing patterns) if the batteryis low or if there is a problem with stimulation. This importantfeedback will alert the patient or clinician to address any issues, suchas battery failure, gel pad detachment, or open connection. In thenon-limiting example with a magnetic lead connector, it is importantthat the stimulator produces an alert if the quick-release cable isaccidentally dislodged without the patient's knowledge. Additionally,lead errors that cause stimulation to stop due to, for example, highelectrode impedance issues (e.g., due to lost connection between skinand return electrode), and can impact therapy usage time and therapeuticbenefit received by the patient and the audible or visible alert of thestimulator prevents this. Further, in one embodiment, the stimulatormemory will generate an activity log for documenting usage of thestimulator and errors during therapy. The stimulator log may include alist of errors that occurred, along with timestamps of the time thaterrors occurred, a history of usage time, including amplitude andstimulation parameter settings used. These features are important toensure that patients are able to effectively use the stimulation andthat clinicians can effectively monitor their stimulation usage.

An additional embodiment of a breakaway mechanism is shown in FIGS. 25Athrough 25D. In FIG. 25A, a portion of the breakaway mechanism is shownas a receptacle portion, including wire/lead contact point CW. Thereceptacle portion may include a magnet M of any appropriate embodimentthat includes a contact point. The receptacle portion may include aniron magnetic stator 1110, which may act as a pathway keeper. FIG. 25Bdepicts a mating portion of the breakaway mechanism, which is a plug1112. The plug may include an iron magnetic keeper path 1113 and acontact 1114. The lead may be operatively attached with the plug 1112.

As shown in FIG. 25C, the breakaway mechanism may include a springloaded plunger mechanism PM. The plunger mechanism utilizes a pair ofbiasing members BM that may push plungers toward each other as the plugis inserted into the receptacle. This may secure the breakaway mechanismtogether. The force utilized to keep the breakaway mechanism together isdefined such that any amount of force applied to the system that exceedssuch force will cause the plug to separate from the receptacle, e.g., ifthere is a force applied to the lead because it snags on something. Thiswill generally protect the system. In particular, it generally preventsthe lead and/or electrode from becoming disengaged or moved from theirintended position.

Although the embodiments of this disclosure have been illustrated in theaccompanying drawings and described in the foregoing detaileddescription, it is to be understood that the present disclosure is notto be limited to just the described embodiments, but that theembodiments described herein are capable of numerous rearrangements,modifications and substitutions without departing from the scope of theclaims hereafter. It is, of course, not possible to describe everyconceivable combination of components or methodologies for purposes ofdescribing the present specification, but one of ordinary skill in theart may recognize that many further combinations and permutations of thepresent specification are possible. Each of the components describedabove may be combined or added together in any permutation to define anintroducing device and/or introducing system. Accordingly, the presentspecification is intended to embrace all such alterations, modificationsand variations that fall within the spirit and scope of the appendedclaims. Furthermore, to the extent that the term “includes” is used ineither the detailed description or the claims, such term is intended tobe inclusive in a manner similar to the term “comprising” as“comprising” is interpreted when employed as a transitional word in aclaim The claims as follows are intended to include all modificationsand alterations insofar as they come within the scope of the claims orthe equivalent thereof.

1. An introducer system for positioning, testing, and deploying a leadfor percutaneous peripheral nerve stimulation, the system comprising: anelectrical stimulus generator unit; a needle assembly including an outersheath having an outer circumference and defining a lumen, an innersheath carried completely within the lumen during positioning andtesting, and a plurality of test electrodes positioned along the outercircumference and electrically communicating with the stimulus generatorunit; a self-anchoring open-coiled helical stimulation lead carriedwithin the inner sheath and having a conductive distal anchor, saidanchor comprising an integrated electrode, and a proximal end incommunication with the stimulus generator unit, a deployment mechanismcooperating relative to the lead and the needle assembly to deploy thelead out of the needle assembly at a selected position identified by thetest electrode during positioning and testing of the system; and whereinthe self-anchoring lead remains confined within the needle assemblyprior to deploying the system and the distal anchor remains deployed intissue after deploying the system.
 2. The system of claim 1, wherein thedeployment mechanism is selected from a plunger and a spacer.
 3. Thesystem of claim 1, wherein two or more test electrodes are provided asan array spaced axially along the outer circumference.
 4. An introducersystem for positioning, testing, and deploying a lead for percutaneousperipheral nerve stimulation, the system comprising: an electricalstimulus generator unit; a needle assembly including an outer sheathhaving an outer circumference and defining a lumen, an inner sheathcarried completely within the lumen during positioning and testing, anda plurality of test electrodes positioned along the axial length of theouter circumference of the outer sheath at spaced-apart intervals andconnected to the stimulus generator unit; a self-anchoring open-coiledhelical stimulation lead carried within the inner sheath and having adistal anchoring electrode through which stimulation can be deliveredand a proximal end in communication with the stimulus generator unit,wherein at least one spacer is movable along an axis of the needleassembly so as to retract the outer sheath at intervals that correspondto one or more positions of the test electrodes; and wherein theself-anchoring lead is deployed at one of the selected locations of oneof the test electrodes as desired.
 5. The introducer system according toclaim 4 further comprising a quick disconnection mechanism formaintaining contact between the proximal end and the stimulus generatorunit.
 6. The introducer system according to claim 5, wherein the quickdisconnection mechanism includes at least one aperture or slot andwherein a proximal end of the electrode is received in the aperture orslot.
 7. The introducer system according to claim 5, wherein the quickdisconnection mechanism includes at least one magnet.
 8. The introducersystem according to claim 5, wherein the quick disconnection mechanismincludes an insulation displacement connector.
 9. The introducer systemaccording to claim 5, wherein the quick disconnection mechanism includesat least one biasing member.
 10. An introducer system for positioning,testing, and deploying a lead for percutaneous peripheral nervestimulation, the system comprising: an electrical stimulus generatorunit; an open-coiled stimulation lead having a conductive distal anchorand a proximal end in communication with the stimulus generator unit, aneedle assembly including an outer sheath having an outer circumferenceand defining a bore, an inner sheath carried completely within the boreduring positioning and testing, and at least one test electrodepositioned along the outer circumference and electrically communicatingwith the stimulus generator unit; wherein the lead is carried with theinner sheath until the lead deployed.
 11. The introducer system of claim5, wherein, when a test mode of the stimulus generator unit isactivated, the at least one test electrode delivers test stimulation atone or more desired positions.
 12. The introducer system of claim 6,wherein the needle assembly can be repeatedly repositioned withoutdeploying the lead.
 13. The introducer system of claim 7, wherein, asthe lead is deployed from the needle assembly, the distal anchor isexposed from the needle assembly and anchors at one of the desiredpositions.